/*
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// Fixed-size string type, for constexpr string handling.
#pragma once
#include <cassert>
#include <cstddef>
#include <initializer_list>
#include <iosfwd>
#include <stdexcept>
#include <string>
#include <string_view>
#include <type_traits>
#include <utility>
#include <folly/ConstexprMath.h>
#include <folly/Portability.h>
#include <folly/Range.h>
#include <folly/Utility.h>
#include <folly/lang/Exception.h>
#include <folly/lang/Ordering.h>
#include <folly/portability/Constexpr.h>
namespace folly {
template <class Char, std::size_t N>
class BasicFixedString;
template <std::size_t N>
using FixedString = BasicFixedString<char, N>;
namespace detail {
namespace fixedstring {
// This is a template so that the class static npos can be defined in the
// header.
template <class = void>
struct FixedStringBase_ {
static constexpr std::size_t npos = static_cast<std::size_t>(-1);
};
using FixedStringBase = FixedStringBase_<>;
// Intentionally NOT constexpr. By making this not constexpr, we make
// checkOverflow below ill-formed in a constexpr context when the condition
// it's testing for fails. In this way, precondition violations are reported
// at compile-time instead of at runtime.
[[noreturn]] inline void assertOutOfBounds() {
assert(false && "Array index out of bounds in BasicFixedString");
throw_exception<std::out_of_range>(
"Array index out of bounds in BasicFixedString");
}
constexpr std::size_t checkOverflow(std::size_t i, std::size_t max) {
return i <= max ? i : (void(assertOutOfBounds()), max);
}
constexpr std::size_t checkOverflowOrNpos(std::size_t i, std::size_t max) {
return i == FixedStringBase::npos
? max
: (i <= max ? i : (void(assertOutOfBounds()), max));
}
constexpr std::size_t checkOverflowIfDebug(std::size_t i, std::size_t size) {
return kIsDebug ? checkOverflow(i, size) : i;
}
// Intentionally NOT constexpr. See note above for assertOutOfBounds
[[noreturn]] inline void assertNotNullTerminated() noexcept {
assert(
false &&
"Non-null terminated string used to initialize a BasicFixedString");
std::terminate(); // Fail hard, fail fast.
}
// Parsing help for human readers: the following is a constexpr noexcept
// function that accepts a reference to an array as a parameter and returns
// a reference to the same array.
template <class Char, std::size_t N>
constexpr const Char (&checkNullTerminated(const Char (&a)[N]) noexcept)[N] {
// Strange decltype(a)(a) used to make MSVC happy.
return a[N - 1u] == Char(0)
// In Debug mode, guard against embedded nulls:
&& (!kIsDebug || N - 1u == folly::constexpr_strlen(a))
? decltype(a)(a)
: (assertNotNullTerminated(), decltype(a)(a));
}
template <class Left, class Right>
constexpr ordering compare_(
const Left& left,
std::size_t left_pos,
std::size_t left_size,
const Right& right,
std::size_t right_pos,
std::size_t right_size) noexcept {
return left_pos == left_size
? (right_pos == right_size ? ordering::eq : ordering::lt)
: (right_pos == right_size ? ordering::gt
: (left[left_pos] < right[right_pos]
? ordering::lt
: (left[left_pos] > right[right_pos]
? ordering::gt
: fixedstring::compare_(
left,
left_pos + 1u,
left_size,
right,
right_pos + 1u,
right_size))));
}
template <class Left, class Right>
constexpr bool equal_(
const Left& left,
std::size_t left_size,
const Right& right,
std::size_t right_size) noexcept {
return left_size == right_size &&
ordering::eq == compare_(left, 0u, left_size, right, 0u, right_size);
}
template <class Char, class Left, class Right>
constexpr Char char_at_(
const Left& left,
std::size_t left_count,
const Right& right,
std::size_t right_count,
std::size_t i) noexcept {
return i < left_count ? left[i]
: i < (left_count + right_count) ? right[i - left_count]
: Char(0);
}
template <class Char, class Left, class Right>
constexpr Char char_at_(
const Left& left,
std::size_t left_size,
std::size_t left_pos,
std::size_t left_count,
const Right& right,
std::size_t right_pos,
std::size_t right_count,
std::size_t i) noexcept {
FOLLY_PUSH_WARNING
#if defined(__GNUC__) && !defined(__clang__) && __GNUC__ <= 13
#pragma GCC diagnostic ignored "-Warray-bounds"
#endif
return i < left_pos
? left[i]
: (i < right_count + left_pos ? right[i - left_pos + right_pos]
: (i < left_size - left_count + right_count
? left[i - right_count + left_count]
: Char(0)));
FOLLY_POP_WARNING
}
template <class Left, class Right>
constexpr bool find_at_(
const Left& left,
const Right& right,
std::size_t pos,
std::size_t count) noexcept {
return 0u == count ||
(left[pos + count - 1u] == right[count - 1u] &&
find_at_(left, right, pos, count - 1u));
}
template <class Char, class Right>
constexpr bool find_one_of_at_(
Char ch, const Right& right, std::size_t pos) noexcept {
return 0u != pos &&
(ch == right[pos - 1u] || find_one_of_at_(ch, right, pos - 1u));
}
template <class Left, class Right>
constexpr std::size_t find_(
const Left& left,
std::size_t left_size,
const Right& right,
std::size_t pos,
std::size_t count) noexcept {
return find_at_(left, right, pos, count) ? pos
: left_size <= pos + count
? FixedStringBase::npos
: find_(left, left_size, right, pos + 1u, count);
}
template <class Left, class Right>
constexpr std::size_t rfind_(
const Left& left,
const Right& right,
std::size_t pos,
std::size_t count) noexcept {
return find_at_(left, right, pos, count) ? pos
: 0u == pos ? FixedStringBase::npos
: rfind_(left, right, pos - 1u, count);
}
template <class Left, class Right>
constexpr std::size_t find_first_of_(
const Left& left,
std::size_t left_size,
const Right& right,
std::size_t pos,
std::size_t count) noexcept {
return find_one_of_at_(left[pos], right, count) ? pos
: left_size <= pos + 1u
? FixedStringBase::npos
: find_first_of_(left, left_size, right, pos + 1u, count);
}
template <class Left, class Right>
constexpr std::size_t find_first_not_of_(
const Left& left,
std::size_t left_size,
const Right& right,
std::size_t pos,
std::size_t count) noexcept {
return !find_one_of_at_(left[pos], right, count) ? pos
: left_size <= pos + 1u
? FixedStringBase::npos
: find_first_not_of_(left, left_size, right, pos + 1u, count);
}
template <class Left, class Right>
constexpr std::size_t find_last_of_(
const Left& left,
const Right& right,
std::size_t pos,
std::size_t count) noexcept {
return find_one_of_at_(left[pos], right, count) ? pos
: 0u == pos ? FixedStringBase::npos
: find_last_of_(left, right, pos - 1u, count);
}
template <class Left, class Right>
constexpr std::size_t find_last_not_of_(
const Left& left,
const Right& right,
std::size_t pos,
std::size_t count) noexcept {
return !find_one_of_at_(left[pos], right, count) ? pos
: 0u == pos ? FixedStringBase::npos
: find_last_not_of_(left, right, pos - 1u, count);
}
struct Helper {
template <class Char, class Left, class Right, std::size_t... Is>
static constexpr BasicFixedString<Char, sizeof...(Is)> concat_(
const Left& left,
std::size_t left_count,
const Right& right,
std::size_t right_count,
std::index_sequence<Is...> is) noexcept {
return {left, left_count, right, right_count, is};
}
template <class Char, class Left, class Right, std::size_t... Is>
static constexpr BasicFixedString<Char, sizeof...(Is)> replace_(
const Left& left,
std::size_t left_size,
std::size_t left_pos,
std::size_t left_count,
const Right& right,
std::size_t right_pos,
std::size_t right_count,
std::index_sequence<Is...> is) noexcept {
return {
left,
left_size,
left_pos,
left_count,
right,
right_pos,
right_count,
is};
}
template <class Char, std::size_t N>
static constexpr const Char (
&data_(const BasicFixedString<Char, N>& that) noexcept)[N + 1u] {
return that.data_;
}
};
template <class T>
constexpr void constexpr_swap(T& a, T& b) noexcept(
noexcept(a = T(std::move(a)))) {
T tmp((std::move(a)));
a = std::move(b);
b = std::move(tmp);
}
// For constexpr reverse iteration over a BasicFixedString
template <class T>
struct ReverseIterator {
private:
T* p_ = nullptr;
struct dummy_ {
T* p_ = nullptr;
};
using other = typename std::conditional<
std::is_const<T>::value,
ReverseIterator<typename std::remove_const<T>::type>,
dummy_>::type;
public:
using value_type = typename std::remove_const<T>::type;
using reference = T&;
using pointer = T*;
using difference_type = std::ptrdiff_t;
using iterator_category = std::random_access_iterator_tag;
constexpr ReverseIterator() = default;
constexpr ReverseIterator(const ReverseIterator&) = default;
constexpr ReverseIterator& operator=(const ReverseIterator&) = default;
constexpr explicit ReverseIterator(T* p) noexcept : p_(p) {}
constexpr /* implicit */ ReverseIterator(const other& that) noexcept
: p_(that.p_) {}
friend constexpr bool operator==(
ReverseIterator a, ReverseIterator b) noexcept {
return a.p_ == b.p_;
}
friend constexpr bool operator!=(
ReverseIterator a, ReverseIterator b) noexcept {
return !(a == b);
}
constexpr reference operator*() const { return *(p_ - 1); }
constexpr ReverseIterator& operator++() noexcept {
--p_;
return *this;
}
constexpr ReverseIterator operator++(int) noexcept {
auto tmp(*this);
--p_;
return tmp;
}
constexpr ReverseIterator& operator--() noexcept {
++p_;
return *this;
}
constexpr ReverseIterator operator--(int) noexcept {
auto tmp(*this);
++p_;
return tmp;
}
constexpr ReverseIterator& operator+=(std::ptrdiff_t i) noexcept {
p_ -= i;
return *this;
}
friend constexpr ReverseIterator operator+(
std::ptrdiff_t i, ReverseIterator that) noexcept {
return ReverseIterator{that.p_ - i};
}
friend constexpr ReverseIterator operator+(
ReverseIterator that, std::ptrdiff_t i) noexcept {
return ReverseIterator{that.p_ - i};
}
constexpr ReverseIterator& operator-=(std::ptrdiff_t i) noexcept {
p_ += i;
return *this;
}
friend constexpr ReverseIterator operator-(
ReverseIterator that, std::ptrdiff_t i) noexcept {
return ReverseIterator{that.p_ + i};
}
friend constexpr std::ptrdiff_t operator-(
ReverseIterator a, ReverseIterator b) noexcept {
return b.p_ - a.p_;
}
constexpr reference operator[](std::ptrdiff_t i) const noexcept {
return *(*this + i);
}
};
} // namespace fixedstring
} // namespace detail
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** *
* \class BasicFixedString
*
* \tparam Char The character type. Must be a scalar type.
* \tparam N The capacity and max size of string instances of this type.
*
* \brief A class for holding up to `N` characters of type `Char` that is
* amenable to `constexpr` string manipulation. It is guaranteed to not
* perform any dynamic allocation.
*
* `BasicFixedString` is a `std::string` work-alike that stores characters in an
* internal buffer. It has minor interface differences that make it easy to work
* with strings in a `constexpr` context.
*
* \par Example:
* \par
* \code
* constexpr auto hello = makeFixedString("hello"); // a FixedString<5>
* constexpr auto world = makeFixedString("world"); // a FixedString<5>
* constexpr auto hello_world = hello + ' ' + world + '!'; // a FixedString<12>
* static_assert(hello_world == "hello world!", "neato!");
* \endcode
* \par
* `FixedString<N>` is an alias for `BasicFixedString<char, N>`.
*
* \par Constexpr and In-place Mutation
* \par
* On a C++14 compiler, `BasicFixedString` supports the full `std::string`
* interface as `constexpr` member functions. On a C++11 compiler, the mutating
* members are not `constexpr`, but non-mutating alternatives, which create a
* new string, can be used instead. For example, instead of this:
* \par
* \code
* constexpr FixedString<10> replace_example_cpp14() {
* FixedString<10> test{"****"};
* test.replace(1, 2, "!!!!");
* return test; // returns "*!!!!*"
* }
* \endcode
* \par
* You might write this instead:
* \par
* \code
* constexpr FixedString<10> replace_example_cpp11() {
* // GNU compilers have an extension that make it possible to create
* // FixedString objects with a `""_fs` user-defined literal.
* using namespace folly;
* return makeFixedString("****").creplace(1, 2, "!!!!"); // "*!!!!*"
* }
* \endcode
*
* \par User-defined Literals
* Instead of using the `folly::makeFixedString` helper function, you can use
* a user-defined literal to make `FixedString` instances. The UDL feature of
* C++ has some limitations that make this less than ideal; you must tell the
* compiler roughly how many characters are in the string. The suffixes `_fs4`,
* `_fs8`, `_fs16`, `_fs32`, `_fs64`, and `_fs128` exist to create instances
* of types `FixedString<4>`, `FixedString<8>`, etc. For example:
* \par
* \code
* using namespace folly::string_literals;
* constexpr auto hello = "hello"_fs8; // A FixedString<8> containing "hello"
* \endcode
* \par
* See Error Handling below for what to expect when you try to exceed the
* capacity of a `FixedString` by storing too many characters in it.
* \par
* If your compiler supports GNU extensions, there is one additional suffix you
* can use: `_fs`. This suffix always creates `FixedString` objects of exactly
* the right size. For example:
* \par
* \code
* using namespace folly::string_literals;
* // NOTE: Only works on compilers with GNU extensions enabled. Clang and
* // gcc support this (-Wgnu-string-literal-operator-template):
* constexpr auto hello = "hello"_fs; // A FixedString<5> containing "hello"
* \endcode
*
* \par Error Handling:
* The capacity of a `BasicFixedString` is set at compile time. When the user
* asks the string to exceed its capacity, one of three things will happen,
* depending on the context:
*\par
* -# If the attempt is made while evaluating a constant expression, the
* program will fail to compile.
* -# Otherwise, if the program is being run in debug mode, it will `assert`.
* -# Otherwise, the failed operation will throw a `std::out_of_range`
* exception.
*\par
* This is also the case if an invalid offset is passed to any member function,
* or if `pop_back` or `cpop_back` is called on an empty `BasicFixedString`.
*
* Member functions documented as having preconditions will assert in Debug
* mode (`!defined(NDEBUG)`) on precondition failures. Those documented with
* \b Throws clauses will throw the specified exception on failure. Those with
* both a precondition and a \b Throws clause will assert in Debug and throw
* in Release mode.
*/
template <class Char, std::size_t N>
class BasicFixedString : private detail::fixedstring::FixedStringBase {
private:
template <class, std::size_t>
friend class BasicFixedString;
friend struct detail::fixedstring::Helper;
// FUTURE: use constexpr_log2 to fold instantiations of BasicFixedString
// together. All BasicFixedString<C, N> instantiations could share the
// implementation of BasicFixedString<C, M>, where M is the next highest power
// of 2 after N.
//
// Also, because of alignment of the data_ and size_ members, N should never
// be smaller than `(alignof(std::size_t)/sizeof(C))-1` (-1 because of the
// null terminator). OR, create a specialization for BasicFixedString<C, 0u>
// that does not have a size_ member, since it is unnecessary.
Char data_[N + 1u]; // +1 for the null terminator
std::size_t size_; // Nbr of chars, not incl. null terminator. size_ <= N.
using Indices = std::make_index_sequence<N>;
template <class That, std::size_t... Is>
constexpr BasicFixedString(
const That& that,
std::size_t size,
std::index_sequence<Is...>,
std::size_t pos = 0,
std::size_t count = npos) noexcept
: data_{(Is < (size - pos) && Is < count ? that[Is + pos] : Char(0))..., Char(0)},
size_{folly::constexpr_min(size - pos, count)} {}
template <std::size_t... Is>
constexpr BasicFixedString(
std::size_t count, Char ch, std::index_sequence<Is...>) noexcept
: data_{((Is < count) ? ch : Char(0))..., Char(0)}, size_{count} {}
// Concatenation constructor
template <class Left, class Right, std::size_t... Is>
constexpr BasicFixedString(
const Left& left,
std::size_t left_size,
const Right& right,
std::size_t right_size,
std::index_sequence<Is...>) noexcept
: data_{detail::fixedstring::char_at_<Char>(left, left_size, right, right_size, Is)..., Char(0)},
size_{left_size + right_size} {}
// Replace constructor
template <class Left, class Right, std::size_t... Is>
constexpr BasicFixedString(
const Left& left,
std::size_t left_size,
std::size_t left_pos,
std::size_t left_count,
const Right& right,
std::size_t right_pos,
std::size_t right_count,
std::index_sequence<Is...>) noexcept
: data_{detail::fixedstring::char_at_<Char>(left, left_size, left_pos, left_count, right, right_pos, right_count, Is)..., Char(0)},
size_{left_size - left_count + right_count} {}
public:
using size_type = std::size_t;
using difference_type = std::ptrdiff_t;
using reference = Char&;
using const_reference = const Char&;
using pointer = Char*;
using const_pointer = const Char*;
using iterator = Char*;
using const_iterator = const Char*;
using reverse_iterator = detail::fixedstring::ReverseIterator<Char>;
using const_reverse_iterator =
detail::fixedstring::ReverseIterator<const Char>;
using detail::fixedstring::FixedStringBase::npos;
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Default construct
* \post `size() == 0`
* \post `at(0) == Char(0)`
*/
constexpr BasicFixedString() : data_{}, size_{} {}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Copy construct
* \post `size() == that.size()`
* \post `0 == strncmp(data(), that.data(), size())`
* \post `at(size()) == Char(0)`
*/
constexpr BasicFixedString(const BasicFixedString& /*that*/) = default;
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Construct from a differently-sized BasicFixedString
* \pre `that.size() <= N`
* \post `size() == that.size()`
* \post `0 == strncmp(data(), that.data(), size())`
* \post `at(size()) == Char(0)`
* \throw std::out_of_range when that.size() > N. When M <= N, this
* constructor will never throw.
* \note Conversions from larger-capacity BasicFixedString objects to smaller
* ones (`M > N`) are allowed as long as the *size()* of the source string
* is small enough.
*/
template <std::size_t M>
constexpr /* implicit */ BasicFixedString(
const BasicFixedString<Char, M>& that) noexcept(M <= N)
: BasicFixedString{that, 0u, that.size_} {}
// Why is this deleted? To avoid confusion with the constructor that takes
// a const Char* and a count.
template <std::size_t M>
constexpr BasicFixedString(
const BasicFixedString<Char, M>& that,
std::size_t pos) noexcept(false) = delete;
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Construct from an BasicFixedString, an offset, and a count
* \param that The source string
* \param pos The starting position in `that`
* \param count The number of characters to copy. If `npos`, `count` is taken
* to be `that.size()-pos`.
* \pre `pos <= that.size()`
* \pre `count <= that.size()-pos && count <= N`
* \post `size() == count`
* \post `0 == strncmp(data(), that.data()+pos, size())`
* \post `at(size()) == Char(0)`
* \throw std::out_of_range when pos+count > that.size(), or when
* `count > N`
*/
template <std::size_t M>
constexpr BasicFixedString(
const BasicFixedString<Char, M>& that,
std::size_t pos,
std::size_t count) noexcept(false)
: BasicFixedString{
that.data_,
that.size_,
std::make_index_sequence<(M < N ? M : N)>{},
pos,
detail::fixedstring::checkOverflow(
detail::fixedstring::checkOverflowOrNpos(
count,
that.size_ -
detail::fixedstring::checkOverflow(pos, that.size_)),
N)} {}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Construct from a string literal
* \pre `M-1 <= N`
* \pre `that[M-1] == Char(0)`
* \post `0 == strncmp(data(), that, M-1)`
* \post `size() == M-1`
* \post `at(size()) == Char(0)`
*/
template <std::size_t M, class = typename std::enable_if<(M - 1u <= N)>::type>
constexpr /* implicit */ BasicFixedString(const Char (&that)[M]) noexcept
: BasicFixedString{
detail::fixedstring::checkNullTerminated(that),
M - 1u,
std::make_index_sequence<M - 1u>{}} {}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Construct from a `const Char*` and count
* \pre `that` points to an array of at least `count` characters.
* \pre `count <= N`
* \post `size() == count`
* \post `0 == strncmp(data(), that, size())`
* \post `at(size()) == Char(0)`
* \throw std::out_of_range when count > N
*/
constexpr BasicFixedString(const Char* that, std::size_t count) noexcept(
false)
: BasicFixedString{
that, detail::fixedstring::checkOverflow(count, N), Indices{}} {}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Construct from a `std::basic_string_view<Char>`
* \param that The source basic_string_view
* \pre `that.size() <= N`
* \post `size() == that.size()`
* \post `0 == strncmp(data(), that.begin(), size())`
* \post `at(size()) == Char(0)`
* \throw std::out_of_range when that.size() > N
*/
constexpr /* implicit */ BasicFixedString(
std::basic_string_view<Char> that) noexcept(false)
: BasicFixedString{that.data(), that.size()} {}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Construct an BasicFixedString that contains `count` characters, all
* of which are `ch`.
* \pre `count <= N`
* \post `size() == count`
* \post `npos == find_first_not_of(ch)`
* \post `at(size()) == Char(0)`
* \throw std::out_of_range when count > N
*/
constexpr BasicFixedString(std::size_t count, Char ch) noexcept(false)
: BasicFixedString{
detail::fixedstring::checkOverflow(count, N), ch, Indices{}} {}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Construct an BasicFixedString from a `std::initializer_list` of
* characters.
* \pre `il.size() <= N`
* \post `size() == count`
* \post `0 == strncmp(data(), il.begin(), size())`
* \post `at(size()) == Char(0)`
* \throw std::out_of_range when il.size() > N
*/
constexpr BasicFixedString(std::initializer_list<Char> il) noexcept(false)
: BasicFixedString{il.begin(), il.size()} {}
constexpr BasicFixedString& operator=(const BasicFixedString&) noexcept =
default;
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Assign from a `BasicFixedString<Char, M>`.
* \pre `that.size() <= N`
* \post `size() == that.size()`
* \post `0 == strncmp(data(), that.begin(), size())`
* \post `at(size()) == Char(0)`
* \throw std::out_of_range when that.size() > N. When M <= N, this
* assignment operator will never throw.
* \note Assignments from larger-capacity BasicFixedString objects to smaller
* ones (`M > N`) are allowed as long as the *size* of the source string is
* small enough.
* \return `*this`
*/
template <std::size_t M>
constexpr BasicFixedString& operator=(
const BasicFixedString<Char, M>& that) noexcept(M <= N) {
detail::fixedstring::checkOverflow(that.size_, N);
size_ = that.copy(data_, that.size_);
data_[size_] = Char(0);
return *this;
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Assign from a null-terminated array of characters.
* \pre `M < N`
* \pre `that` has no embedded null characters
* \pre `that[M-1]==Char(0)`
* \post `size() == M-1`
* \post `0 == strncmp(data(), that, size())`
* \post `at(size()) == Char(0)`
* \return `*this`
*/
template <std::size_t M, class = typename std::enable_if<(M - 1u <= N)>::type>
constexpr BasicFixedString& operator=(const Char (&that)[M]) noexcept {
return assign(detail::fixedstring::checkNullTerminated(that), M - 1u);
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Assign from an `initializer_list` of characters.
* \pre `il.size() <= N`
* \post `size() == il.size()`
* \post `0 == strncmp(data(), il.begin(), size())`
* \post `at(size()) == Char(0)`
* \throw std::out_of_range when il.size() > N
* \return `*this`
*/
constexpr BasicFixedString& operator=(
std::initializer_list<Char> il) noexcept(false) {
detail::fixedstring::checkOverflow(il.size(), N);
for (std::size_t i = 0u; i < il.size(); ++i) {
data_[i] = il.begin()[i];
}
size_ = il.size();
data_[size_] = Char(0);
return *this;
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Conversion to folly::Range
* \return `Range<Char*>{begin(), end()}`
*/
constexpr Range<Char*> toRange() noexcept { return {begin(), end()}; }
/**
* \overload
*/
constexpr Range<const Char*> toRange() const noexcept {
return {begin(), end()};
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Conversion to std::basic_string<Char>
* \return `std::basic_string<Char>{begin(), end()}`
*/
/* implicit */ operator std::basic_string<Char>() const noexcept(false) {
return std::basic_string<Char>{begin(), end()};
}
std::basic_string<Char> toStdString() const noexcept(false) {
return std::basic_string<Char>{begin(), end()};
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Conversion to std::basic_string_view<Char>
* \return `std::basic_string_view<Char>{begin(), end()}`
*/
/* implicit */ constexpr operator std::basic_string_view<Char>() const {
return std::basic_string_view<Char>{begin(), size()};
}
// Think hard about whether this is a good idea. It's certainly better than
// an implicit conversion to `const Char*` since `delete "hi"_fs` will fail
// to compile. But it creates ambiguities when passing a FixedString to an
// API that has overloads for `const char*` and `folly::Range`, for instance.
// using ArrayType = Char[N];
// constexpr /* implicit */ operator ArrayType&() noexcept {
// return data_;
// }
// using ConstArrayType = const Char[N];
// constexpr /* implicit */ operator ConstArrayType&() const noexcept {
// return data_;
// }
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Assigns a sequence of `count` characters of value `ch`.
* \param count The count of characters.
* \param ch
* \pre `count <= N`
* \post `size() == count`
* \post `npos == find_first_not_of(ch)`
* \post `at(size()) == Char(0)`
* \throw std::out_of_range when count > N
* \return `*this`
*/
constexpr BasicFixedString& assign(std::size_t count, Char ch) noexcept(
false) {
detail::fixedstring::checkOverflow(count, N);
for (std::size_t i = 0u; i < count; ++i) {
data_[i] = ch;
}
size_ = count;
data_[size_] = Char(0);
return *this;
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Assigns characters from an `BasicFixedString` to this object.
* \note Equivalent to `assign(that, 0, that.size())`
*/
template <std::size_t M>
constexpr BasicFixedString& assign(
const BasicFixedString<Char, M>& that) noexcept(M <= N) {
return *this = that;
}
// Why is this overload deleted? So users aren't confused by the difference
// between str.assign("foo", N) and str.assign("foo"_fs, N). In the former,
// N is a count of characters. In the latter, it would be a position, which
// totally changes the meaning of the code.
template <std::size_t M>
constexpr BasicFixedString& assign(
const BasicFixedString<Char, M>& that,
std::size_t pos) noexcept(false) = delete;
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Assigns `count` characters from an `BasicFixedString` to this object,
* starting at position `pos` in the source object.
* \param that The source string.
* \param pos The starting position in the source string.
* \param count The number of characters to copy. If `npos`, `count` is taken
* to be `that.size()-pos`.
* \pre `pos <= that.size()`
* \pre `count <= that.size()-pos`
* \pre `count <= N`
* \post `size() == count`
* \post `0 == strncmp(data(), that.begin() + pos, count)`
* \post `at(size()) == Char(0)`
* \throw std::out_of_range when pos > that.size() or count > that.size()-pos
* or count > N.
* \return `*this`
*/
template <std::size_t M>
constexpr BasicFixedString& assign(
const BasicFixedString<Char, M>& that,
std::size_t pos,
std::size_t count) noexcept(false) {
detail::fixedstring::checkOverflow(pos, that.size_);
return assign(
that.data_ + pos,
detail::fixedstring::checkOverflowOrNpos(count, that.size_ - pos));
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Assigns characters from an `BasicFixedString` to this object.
* \pre `that` contains no embedded nulls.
* \pre `that[M-1] == Char(0)`
* \note Equivalent to `assign(that, M - 1)`
*/
template <std::size_t M, class = typename std::enable_if<(M - 1u <= N)>::type>
constexpr BasicFixedString& assign(const Char (&that)[M]) noexcept {
return assign(detail::fixedstring::checkNullTerminated(that), M - 1u);
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Assigns `count` characters from a range of characters to this object.
* \param that A pointer to a range of characters.
* \param count The number of characters to copy.
* \pre `that` points to at least `count` characters.
* \pre `count <= N`
* \post `size() == count`
* \post `0 == strncmp(data(), that, count)`
* \post `at(size()) == Char(0)`
* \throw std::out_of_range when count > N
* \return `*this`
*/
constexpr BasicFixedString& assign(
const Char* that, std::size_t count) noexcept(false) {
detail::fixedstring::checkOverflow(count, N);
for (std::size_t i = 0u; i < count; ++i) {
data_[i] = that[i];
}
size_ = count;
data_[size_] = Char(0);
return *this;
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Swap the contents of this string with `that`.
*/
constexpr void swap(BasicFixedString& that) noexcept {
// less-than-or-equal here to copy the null terminator:
for (std::size_t i = 0u; i <= folly::constexpr_max(size_, that.size_);
++i) {
detail::fixedstring::constexpr_swap(data_[i], that.data_[i]);
}
detail::fixedstring::constexpr_swap(size_, that.size_);
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Return a pointer to a range of `size()+1` characters, the last of which
* is `Char(0)`.
*/
constexpr Char* data() noexcept { return data_; }
/**
* \overload
*/
constexpr const Char* data() const noexcept { return data_; }
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* \return `data()`.
*/
constexpr const Char* c_str() const noexcept { return data_; }
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* \return `data()`.
*/
constexpr Char* begin() noexcept { return data_; }
/**
* \overload
*/
constexpr const Char* begin() const noexcept { return data_; }
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* \return `data()`.
*/
constexpr const Char* cbegin() const noexcept { return begin(); }
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* \return `data() + size()`.
*/
constexpr Char* end() noexcept { return data_ + size_; }
/**
* \overload
*/
constexpr const Char* end() const noexcept { return data_ + size_; }
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* \return `data() + size()`.
*/
constexpr const Char* cend() const noexcept { return end(); }
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Returns a reverse iterator to the first character of the reversed string.
* It corresponds to the last + 1 character of the non-reversed string.
*/
constexpr reverse_iterator rbegin() noexcept {
return reverse_iterator{data_ + size_};
}
/**
* \overload
*/
constexpr const_reverse_iterator rbegin() const noexcept {
return const_reverse_iterator{data_ + size_};
}
/**
* \note Equivalent to `rbegin()` on a const-qualified reference to `*this`.
*/
constexpr const_reverse_iterator crbegin() const noexcept { return rbegin(); }
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Returns a reverse iterator to the last + 1 character of the reversed
* string. It corresponds to the first character of the non-reversed string.
*/
constexpr reverse_iterator rend() noexcept { return reverse_iterator{data_}; }
/**
* \overload
*/
constexpr const_reverse_iterator rend() const noexcept {
return const_reverse_iterator{data_};
}
/**
* \note Equivalent to `rend()` on a const-qualified reference to `*this`.
*/
constexpr const_reverse_iterator crend() const noexcept { return rend(); }
/**
* \return The number of `Char` elements in the string.
*/
constexpr std::size_t size() const noexcept { return size_; }
/**
* \return The number of `Char` elements in the string.
*/
constexpr std::size_t length() const noexcept { return size_; }
/**
* \return True if and only if `size() == 0`.
*/
constexpr bool empty() const noexcept { return 0u == size_; }
/**
* \return `N`.
*/
static constexpr std::size_t capacity() noexcept { return N; }
/**
* \return `N`.
*/
static constexpr std::size_t max_size() noexcept { return N; }
/**
* \note `at(size())` is allowed will return `Char(0)`.
* \return `*(data() + i)`
* \throw std::out_of_range when i > size()
*/
constexpr Char& at(std::size_t i) noexcept(false) {
return i <= size_ ? data_[i]
: (throw_exception<std::out_of_range>(
"Out of range in BasicFixedString::at"),
data_[size_]);
}
/**
* \overload
*/
constexpr const Char& at(std::size_t i) const noexcept(false) {
return i <= size_ ? data_[i]
: (throw_exception<std::out_of_range>(
"Out of range in BasicFixedString::at"),
data_[size_]);
}
/**
* \pre `i <= size()`
* \note `(*this)[size()]` is allowed will return `Char(0)`.
* \return `*(data() + i)`
*/
constexpr Char& operator[](std::size_t i) noexcept {
return data_[detail::fixedstring::checkOverflowIfDebug(i, size_)];
}
/**
* \overload
*/
constexpr const Char& operator[](std::size_t i) const noexcept {
return data_[detail::fixedstring::checkOverflowIfDebug(i, size_)];
}
/**
* \note Equivalent to `(*this)[0]`
*/
constexpr Char& front() noexcept { return (*this)[0u]; }
/**
* \overload
*/
constexpr const Char& front() const noexcept { return (*this)[0u]; }
/**
* \note Equivalent to `at(size()-1)`
* \pre `!empty()`
*/
constexpr Char& back() noexcept {
return data_[size_ - detail::fixedstring::checkOverflowIfDebug(1u, size_)];
}
/**
* \overload
*/
constexpr const Char& back() const noexcept {
return data_[size_ - detail::fixedstring::checkOverflowIfDebug(1u, size_)];
}
/**
* Clears the contents of this string.
* \post `size() == 0u`
* \post `at(size()) == Char(0)`
*/
constexpr void clear() noexcept {
data_[0u] = Char(0);
size_ = 0u;
}
/**
* \note Equivalent to `append(1u, ch)`.
*/
constexpr void push_back(Char ch) noexcept(false) {
detail::fixedstring::checkOverflow(1u, N - size_);
data_[size_] = ch;
data_[++size_] = Char(0);
}
/**
* \note Equivalent to `cappend(1u, ch)`.
*/
constexpr BasicFixedString<Char, N + 1u> cpush_back(Char ch) const noexcept {
return cappend(ch);
}
/**
* Removes the last character from the string.
* \pre `!empty()`
* \post `size()` is one fewer than before calling `pop_back()`.
* \post `at(size()) == Char(0)`
* \post The characters in the half-open range `[0,size()-1)` are unmodified.
* \throw std::out_of_range if empty().
*/
constexpr void pop_back() noexcept(false) {
detail::fixedstring::checkOverflow(1u, size_);
--size_;
data_[size_] = Char(0);
}
/**
* Returns a new string with the first `size()-1` characters from this string.
* \pre `!empty()`
* \note Equivalent to `BasicFixedString<Char, N-1u>{*this, 0u, size()-1u}`
* \throw std::out_of_range if empty().
*/
constexpr BasicFixedString<Char, N - 1u> cpop_back() const noexcept(false) {
return {*this, 0u, size_ - detail::fixedstring::checkOverflow(1u, size_)};
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Appends `count` copies of `ch` to this string.
* \pre `count + old_size <= N`
* \post The first `old_size` characters of the string are unmodified.
* \post `size() == old_size + count`
* \throw std::out_of_range if count > N - size().
*/
constexpr BasicFixedString& append(std::size_t count, Char ch) noexcept(
false) {
detail::fixedstring::checkOverflow(count, N - size_);
for (std::size_t i = 0u; i < count; ++i) {
data_[size_ + i] = ch;
}
size_ += count;
data_[size_] = Char(0);
return *this;
}
/**
* \note Equivalent to `append(*this, 0, that.size())`.
*/
template <std::size_t M>
constexpr BasicFixedString& append(
const BasicFixedString<Char, M>& that) noexcept(false) {
return append(that, 0u, that.size_);
}
// Why is this overload deleted? So as not to get confused with
// append("null-terminated", N), where N would be a count instead
// of a position.
template <std::size_t M>
constexpr BasicFixedString& append(
const BasicFixedString<Char, M>& that,
std::size_t pos) noexcept(false) = delete;
/**
* Appends `count` characters from another string to this one, starting at a
* given offset, `pos`.
* \param that The source string.
* \param pos The starting position in the source string.
* \param count The number of characters to append. If `npos`, `count` is
* taken to be `that.size()-pos`.
* \pre `pos <= that.size()`
* \pre `count <= that.size() - pos`
* \pre `old_size + count <= N`
* \post The first `old_size` characters of the string are unmodified.
* \post `size() == old_size + count`
* \post `at(size()) == Char(0)`
* \throw std::out_of_range if pos + count > that.size() or if
* `old_size + count > N`.
*/
template <std::size_t M>
constexpr BasicFixedString& append(
const BasicFixedString<Char, M>& that,
std::size_t pos,
std::size_t count) noexcept(false) {
detail::fixedstring::checkOverflow(pos, that.size_);
count = detail::fixedstring::checkOverflowOrNpos(count, that.size_ - pos);
detail::fixedstring::checkOverflow(count, N - size_);
for (std::size_t i = 0u; i < count; ++i) {
data_[size_ + i] = that.data_[pos + i];
}
size_ += count;
data_[size_] = Char(0);
return *this;
}
/**
* \note Equivalent to `append(that, strlen(that))`.
*/
constexpr BasicFixedString& append(const Char* that) noexcept(false) {
return append(that, folly::constexpr_strlen(that));
}
/**
* Appends `count` characters from the specified character array.
* \pre `that` points to a range of at least `count` characters.
* \pre `count + old_size <= N`
* \post The first `old_size` characters of the string are unmodified.
* \post `size() == old_size + count`
* \post `at(size()) == Char(0)`
* \throw std::out_of_range if old_size + count > N.
*/
constexpr BasicFixedString& append(
const Char* that, std::size_t count) noexcept(false) {
detail::fixedstring::checkOverflow(count, N - size_);
for (std::size_t i = 0u; i < count; ++i) {
data_[size_ + i] = that[i];
}
size_ += count;
data_[size_] = Char(0);
return *this;
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Creates a new string by appending a character to an existing string, which
* is left unmodified.
* \note Equivalent to `*this + ch`
*/
constexpr BasicFixedString<Char, N + 1u> cappend(Char ch) const noexcept {
return *this + ch;
}
/**
* Creates a new string by appending a string to an existing string, which
* is left unmodified.
* \note Equivalent to `*this + ch`
*/
template <std::size_t M>
constexpr BasicFixedString<Char, N + M> cappend(
const BasicFixedString<Char, M>& that) const noexcept {
return *this + that;
}
// Deleted to avoid confusion with append("char*", N), where N is a count
// instead of a position.
template <std::size_t M>
constexpr BasicFixedString<Char, N + M> cappend(
const BasicFixedString<Char, M>& that, std::size_t pos) const
noexcept(false) = delete;
/**
* Creates a new string by appending characters from one string to another,
* which is left unmodified.
* \note Equivalent to `*this + that.substr(pos, count)`
*/
template <std::size_t M>
constexpr BasicFixedString<Char, N + M> cappend(
const BasicFixedString<Char, M>& that,
std::size_t pos,
std::size_t count) const noexcept(false) {
return creplace(size_, 0u, that, pos, count);
}
/**
* Creates a new string by appending a string literal to a string,
* which is left unmodified.
* \note Equivalent to `*this + that`
*/
template <std::size_t M>
constexpr BasicFixedString<Char, N + M - 1u> cappend(
const Char (&that)[M]) const noexcept {
return creplace(size_, 0u, that);
}
// Deleted to avoid confusion with append("char*", N), where N is a count
// instead of a position
template <std::size_t M>
constexpr BasicFixedString<Char, N + M - 1u> cappend(
const Char (&that)[M], std::size_t pos) const noexcept(false) = delete;
/**
* Creates a new string by appending characters from one string to another,
* which is left unmodified.
* \note Equivalent to `*this + makeFixedString(that).substr(pos, count)`
*/
template <std::size_t M>
constexpr BasicFixedString<Char, N + M - 1u> cappend(
const Char (&that)[M], std::size_t pos, std::size_t count) const
noexcept(false) {
return creplace(size_, 0u, that, pos, count);
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Appends characters from a null-terminated string literal to this string.
* \note Equivalent to `append(that)`.
*/
constexpr BasicFixedString& operator+=(const Char* that) noexcept(false) {
return append(that);
}
/**
* Appends characters from another string to this one.
* \note Equivalent to `append(that)`.
*/
template <std::size_t M>
constexpr BasicFixedString& operator+=(
const BasicFixedString<Char, M>& that) noexcept(false) {
return append(that, 0u, that.size_);
}
/**
* Appends a character to this string.
* \note Equivalent to `push_back(ch)`.
*/
constexpr BasicFixedString& operator+=(Char ch) noexcept(false) {
push_back(ch);
return *this;
}
/**
* Appends characters from an `initializer_list` to this string.
* \note Equivalent to `append(il.begin(), il.size())`.
*/
constexpr BasicFixedString& operator+=(
std::initializer_list<Char> il) noexcept(false) {
return append(il.begin(), il.size());
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Erase all characters from this string.
* \note Equivalent to `clear()`
* \return *this;
*/
constexpr BasicFixedString& erase() noexcept {
clear();
return *this;
}
/**
* Erases `count` characters from position `pos`. If `count` is `npos`,
* erases from `pos` to the end of the string.
* \pre `pos <= size()`
* \pre `count <= size() - pos || count == npos`
* \post `size() == old_size - min(count, old_size - pos)`
* \post `at(size()) == Char(0)`
* \return *this;
* \throw std::out_of_range when pos > size().
*/
constexpr BasicFixedString& erase(
std::size_t pos, std::size_t count = npos) noexcept(false) {
using A = const Char[1];
constexpr A a{Char(0)};
return replace(
pos,
detail::fixedstring::checkOverflowOrNpos(
count, size_ - detail::fixedstring::checkOverflow(pos, size_)),
a,
0u);
}
/**
* \note Equivalent to `erase(first - data(), 1)`
* \return A pointer to the first character after the erased character.
*/
constexpr Char* erase(const Char* first) noexcept(false) {
erase(first - data_, 1u);
return data_ + (first - data_);
}
/**
* \note Equivalent to `erase(first - data(), last - first)`
* \return A pointer to the first character after the erased characters.
*/
constexpr Char* erase(const Char* first, const Char* last) noexcept(false) {
erase(first - data_, last - first);
return data_ + (first - data_);
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Create a new string by erasing all the characters from this string.
* \note Equivalent to `BasicFixedString<Char, 0>{}`
*/
constexpr BasicFixedString<Char, 0u> cerase() const noexcept { return {}; }
/**
* Create a new string by erasing all the characters after position `pos` from
* this string.
* \note Equivalent to `creplace(pos, min(count, pos - size()), "")`
*/
constexpr BasicFixedString cerase(
std::size_t pos, std::size_t count = npos) const noexcept(false) {
using A = const Char[1];
return creplace(
pos,
detail::fixedstring::checkOverflowOrNpos(
count, size_ - detail::fixedstring::checkOverflow(pos, size_)),
A{Char(0)});
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Compare two strings for lexicographical ordering.
* \note Equivalent to
* `compare(0, size(), that.data(), that.size())`
*/
template <std::size_t M>
constexpr int compare(const BasicFixedString<Char, M>& that) const noexcept {
return compare(0u, size_, that, 0u, that.size_);
}
/**
* Compare two strings for lexicographical ordering.
* \note Equivalent to
* `compare(this_pos, this_count, that.data(), that.size())`
*/
template <std::size_t M>
constexpr int compare(
std::size_t this_pos,
std::size_t this_count,
const BasicFixedString<Char, M>& that) const noexcept(false) {
return compare(this_pos, this_count, that, 0u, that.size_);
}
/**
* Compare two strings for lexicographical ordering.
* \note Equivalent to
* `compare(this_pos, this_count, that.data() + that_pos, that_count)`
*/
template <std::size_t M>
constexpr int compare(
std::size_t this_pos,
std::size_t this_count,
const BasicFixedString<Char, M>& that,
std::size_t that_pos,
std::size_t that_count) const noexcept(false) {
return static_cast<int>(detail::fixedstring::compare_(
data_,
detail::fixedstring::checkOverflow(this_pos, size_),
detail::fixedstring::checkOverflow(this_count, size_ - this_pos) +
this_pos,
that.data_,
detail::fixedstring::checkOverflow(that_pos, that.size_),
detail::fixedstring::checkOverflow(that_count, that.size_ - that_pos) +
that_pos));
}
/**
* Compare two strings for lexicographical ordering.
* \note Equivalent to `compare(0, size(), that, strlen(that))`
*/
constexpr int compare(const Char* that) const noexcept {
return compare(0u, size_, that, folly::constexpr_strlen(that));
}
/**
* \overload
*/
constexpr int compare(Range<const Char*> that) const noexcept {
return compare(0u, size_, that.begin(), that.size());
}
/**
* Compare two strings for lexicographical ordering.
* \note Equivalent to
* `compare(this_pos, this_count, that, strlen(that))`
*/
constexpr int compare(
std::size_t this_pos, std::size_t this_count, const Char* that) const
noexcept(false) {
return compare(this_pos, this_count, that, folly::constexpr_strlen(that));
}
/**
* \overload
*/
constexpr int compare(
std::size_t this_pos,
std::size_t this_count,
Range<const Char*> that) const noexcept(false) {
return compare(this_pos, this_count, that.begin(), that.size());
}
/**
* Compare two strings for lexicographical ordering.
*
* Let `A` be the
* character sequence {`(*this)[this_pos]`, ...
* `(*this)[this_pos + this_count - 1]`}. Let `B` be the character sequence
* {`that[0]`, ...`that[count - 1]`}. Then...
*
* \return
* - `< 0` if `A` is ordered before the `B`
* - `> 0` if `B` is ordered before `A`
* - `0` if `A` equals `B`.
*
* \throw std::out_of_range if this_pos + this_count > size().
*/
constexpr int compare(
std::size_t this_pos,
std::size_t this_count,
const Char* that,
std::size_t that_count) const noexcept(false) {
return static_cast<int>(detail::fixedstring::compare_(
data_,
detail::fixedstring::checkOverflow(this_pos, size_),
detail::fixedstring::checkOverflowOrNpos(this_count, size_ - this_pos) +
this_pos,
that,
0u,
that_count));
}
constexpr int compare(
std::size_t this_pos,
std::size_t this_count,
Range<const Char*> that,
std::size_t that_count) const noexcept(false) {
return compare(
this_pos,
this_count,
that.begin(),
detail::fixedstring::checkOverflow(that_count, that.size()));
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Return a substring from `pos` to the end of the string.
* \note Equivalent to `BasicFixedString{*this, pos}`
*/
constexpr BasicFixedString substr(std::size_t pos) const noexcept(false) {
return {*this, pos};
}
/**
* Return a substring from `pos` to the end of the string.
* \note Equivalent to `BasicFixedString{*this, pos, count}`
*/
constexpr BasicFixedString substr(std::size_t pos, std::size_t count) const
noexcept(false) {
return {*this, pos, count};
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Replace the characters in the range denoted by the half-open range
* [`first`, `last`) with the string `that`.
* \pre `first` and `last` point to characters within this string (including
* the terminating null).
* \note Equivalent to
* `replace(first - data(), last - first, that.data(), that.size())`
*/
template <std::size_t M>
constexpr BasicFixedString& replace(
const Char* first,
const Char* last,
const BasicFixedString<Char, M>& that) noexcept(false) {
return replace(first - data_, last - first, that, 0u, that.size_);
}
/**
* Replace `this_count` characters starting from position `this_pos` with the
* characters from string `that` starting at position `that_pos`.
* \pre `that_pos <= that.size()`
* \note Equivalent to
* <tt>replace(this_pos, this_count, that.data() + that_pos,
* that.size() - that_pos)</tt>
*/
template <std::size_t M>
constexpr BasicFixedString& replace(
std::size_t this_pos,
std::size_t this_count,
const BasicFixedString<Char, M>& that,
std::size_t that_pos = 0u) noexcept(false) {
return replace(this_pos, this_count, that, that_pos, that.size_ - that_pos);
}
/**
* Replace `this_count` characters starting from position `this_pos` with
* `that_count` characters from string `that` starting at position
* `that_pos`.
* \pre `that_pos <= that.size() && that_count <= that.size() - that_pos`
* \note Equivalent to
* `replace(this_pos, this_count, that.data() + that_pos, that_count)`
*/
template <std::size_t M>
constexpr BasicFixedString& replace(
std::size_t this_pos,
std::size_t this_count,
const BasicFixedString<Char, M>& that,
std::size_t that_pos,
std::size_t that_count) noexcept(false) {
return *this = creplace(this_pos, this_count, that, that_pos, that_count);
}
/**
* Replace `this_count` characters starting from position `this_pos` with
* the characters from the string literal `that`.
* \note Equivalent to
* `replace(this_pos, this_count, that, strlen(that))`
*/
constexpr BasicFixedString& replace(
std::size_t this_pos,
std::size_t this_count,
const Char* that) noexcept(false) {
return replace(this_pos, this_count, that, folly::constexpr_strlen(that));
}
/**
* Replace the characters denoted by the half-open range [`first`,`last`) with
* the characters from the string literal `that`.
* \pre `first` and `last` point to characters within this string (including
* the terminating null).
* \note Equivalent to
* `replace(first - data(), last - first, that, strlen(that))`
*/
constexpr BasicFixedString& replace(
const Char* first, const Char* last, const Char* that) noexcept(false) {
return replace(
first - data_, last - first, that, folly::constexpr_strlen(that));
}
/**
* Replace `this_count` characters starting from position `this_pos` with
* `that_count` characters from the character sequence pointed to by `that`.
* \param this_pos The starting offset within `*this` of the first character
* to be replaced.
* \param this_count The number of characters to be replaced. If `npos`,
* it is treated as if `this_count` were `size() - this_pos`.
* \param that A pointer to the replacement string.
* \param that_count The number of characters in the replacement string.
* \pre `this_pos <= size() && this_count <= size() - this_pos`
* \pre `that` points to a contiguous sequence of at least `that_count`
* characters
* \throw std::out_of_range on any of the following conditions:
* - `this_pos > size()`
* - `this_count > size() - this_pos`
* - `size() - this_count + that_count > N`
*/
constexpr BasicFixedString& replace(
std::size_t this_pos,
std::size_t this_count,
const Char* that,
std::size_t that_count) noexcept(false) {
return *this = detail::fixedstring::Helper::replace_<Char>(
data_,
size_,
detail::fixedstring::checkOverflow(this_pos, size_),
detail::fixedstring::checkOverflowOrNpos(
this_count, size_ - this_pos),
that,
0u,
that_count,
Indices{});
}
/**
* Replace `this_count` characters starting from position `this_pos` with
* `that_count` characters `ch`.
* \note Equivalent to
* `replace(this_pos, this_count, BasicFixedString{that_count, ch})`
*/
constexpr BasicFixedString& replace(
std::size_t this_pos,
std::size_t this_count,
std::size_t that_count,
Char ch) noexcept(false) {
return replace(this_pos, this_count, BasicFixedString{that_count, ch});
}
/**
* Replace the characters denoted by the half-open range [`first`,`last`)
* with `that_count` characters `ch`.
* \note Equivalent to
* `replace(first - data(), last - first, BasicFixedString{that_count, ch})`
*/
constexpr BasicFixedString& replace(
const Char* first,
const Char* last,
std::size_t that_count,
Char ch) noexcept(false) {
return replace(
first - data_, last - first, BasicFixedString{that_count, ch});
}
/**
* Replace the characters denoted by the half-open range [`first`,`last`) with
* the characters from the string literal `that`.
* \pre `first` and `last` point to characters within this string (including
* the terminating null).
* \note Equivalent to
* `replace(this_pos, this_count, il.begin(), il.size())`
*/
constexpr BasicFixedString& replace(
const Char* first,
const Char* last,
std::initializer_list<Char> il) noexcept(false) {
return replace(first - data_, last - first, il.begin(), il.size());
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Construct a new string by replacing `this_count` characters starting from
* position `this_pos` within this string with the characters from string
* `that` starting at position `that_pos`.
* \pre `that_pos <= that.size()`
* \note Equivalent to
* <tt>creplace(this_pos, this_count, that, that_pos,
* that.size() - that_pos)</tt>
*/
template <std::size_t M>
constexpr BasicFixedString<Char, N + M> creplace(
std::size_t this_pos,
std::size_t this_count,
const BasicFixedString<Char, M>& that,
std::size_t that_pos = 0u) const noexcept(false) {
return creplace(
this_pos,
this_count,
that,
that_pos,
that.size_ - detail::fixedstring::checkOverflow(that_pos, that.size_));
}
/**
* Construct a new string by replacing `this_count` characters starting from
* position `this_pos` within this string with `that_count` characters from
* string `that` starting at position `that_pos`.
* \param this_pos The starting offset within `*this` of the first character
* to be replaced.
* \param this_count The number of characters to be replaced. If `npos`,
* it is treated as if `this_count` were `size() - this_pos`.
* \param that A string that contains the replacement string.
* \param that_pos The offset to the first character in the replacement
* string.
* \param that_count The number of characters in the replacement string.
* \pre `this_pos <= size() && this_count <= size() - this_pos`
* \pre `that_pos <= that.size() && that_count <= that.size() - that_pos`
* \post The size of the returned string is `size() - this_count + that_count`
* \note Equivalent to <tt>BasicFixedString<Char, N + M>{substr(0, this_pos) +
* that.substr(that_pos, that_count) + substr(this_pos + this_count)}</tt>
* \throw std::out_of_range on any of the following conditions:
* - `this_pos > size()`
* - `this_count > size() - this_pos`
* - `that_pos > that.size()`
* - `that_count > that.size() - that_pos`
*/
template <std::size_t M>
constexpr BasicFixedString<Char, N + M> creplace(
std::size_t this_pos,
std::size_t this_count,
const BasicFixedString<Char, M>& that,
std::size_t that_pos,
std::size_t that_count) const noexcept(false) {
return detail::fixedstring::Helper::replace_<Char>(
data_,
size_,
detail::fixedstring::checkOverflow(this_pos, size_),
detail::fixedstring::checkOverflowOrNpos(this_count, size_ - this_pos),
that.data_,
detail::fixedstring::checkOverflow(that_pos, that.size_),
detail::fixedstring::checkOverflowOrNpos(
that_count, that.size_ - that_pos),
std::make_index_sequence<N + M>{});
}
/**
* Construct a new string by replacing the characters denoted by the half-open
* range [`first`,`last`) within this string with the characters from string
* `that` starting at position `that_pos`.
* \pre `that_pos <= that.size()`
* \note Equivalent to
* <tt>creplace(first - data(), last - first, that, that_pos,
* that.size() - that_pos)</tt>
*/
template <std::size_t M>
constexpr BasicFixedString<Char, N + M> creplace(
const Char* first,
const Char* last,
const BasicFixedString<Char, M>& that,
std::size_t that_pos = 0u) const noexcept(false) {
return creplace(
first - data_,
last - first,
that,
that_pos,
that.size_ - detail::fixedstring::checkOverflow(that_pos, that.size_));
}
/**
* Construct a new string by replacing the characters denoted by the half-open
* range [`first`,`last`) within this string with the `that_count`
* characters from string `that` starting at position `that_pos`.
* \note Equivalent to
* <tt>creplace(first - data(), last - first, that, that_pos,
* that_count)</tt>
*/
template <std::size_t M>
constexpr BasicFixedString<Char, N + M> creplace(
const Char* first,
const Char* last,
const BasicFixedString<Char, M>& that,
std::size_t that_pos,
std::size_t that_count) const noexcept(false) {
return creplace(first - data_, last - first, that, that_pos, that_count);
}
/**
* Construct a new string by replacing `this_count` characters starting from
* position `this_pos` within this string with `M-1` characters from
* character array `that`.
* \pre `strlen(that) == M-1`
* \note Equivalent to
* <tt>creplace(this_pos, this_count, that, 0, M - 1)</tt>
*/
template <std::size_t M>
constexpr BasicFixedString<Char, N + M - 1u> creplace(
std::size_t this_pos, std::size_t this_count, const Char (&that)[M]) const
noexcept(false) {
return creplace(this_pos, this_count, that, 0u, M - 1u);
}
/**
* Replace `this_count` characters starting from position `this_pos` with
* `that_count` characters from the character array `that` starting at
* position `that_pos`.
* \param this_pos The starting offset within `*this` of the first character
* to be replaced.
* \param this_count The number of characters to be replaced. If `npos`,
* it is treated as if `this_count` were `size() - this_pos`.
* \param that An array of characters containing the replacement string.
* \param that_pos The starting offset of the replacement string.
* \param that_count The number of characters in the replacement string. If
* `npos`, it is treated as if `that_count` were `M - 1 - that_pos`
* \pre `this_pos <= size() && this_count <= size() - this_pos`
* \pre `that_pos <= M - 1 && that_count <= M - 1 - that_pos`
* \post The size of the returned string is `size() - this_count + that_count`
* \note Equivalent to <tt>BasicFixedString<Char, N + M - 1>{
* substr(0, this_pos) +
* makeFixedString(that).substr(that_pos, that_count) +
* substr(this_pos + this_count)}</tt>
* \throw std::out_of_range on any of the following conditions:
* - `this_pos > size()`
* - `this_count > size() - this_pos`
* - `that_pos >= M`
* - `that_count >= M - that_pos`
*/
template <std::size_t M>
constexpr BasicFixedString<Char, N + M - 1u> creplace(
std::size_t this_pos,
std::size_t this_count,
const Char (&that)[M],
std::size_t that_pos,
std::size_t that_count) const noexcept(false) {
return detail::fixedstring::Helper::replace_<Char>(
data_,
size_,
detail::fixedstring::checkOverflow(this_pos, size_),
detail::fixedstring::checkOverflowOrNpos(this_count, size_ - this_pos),
detail::fixedstring::checkNullTerminated(that),
detail::fixedstring::checkOverflow(that_pos, M - 1u),
detail::fixedstring::checkOverflowOrNpos(that_count, M - 1u - that_pos),
std::make_index_sequence<N + M - 1u>{});
}
/**
* Construct a new string by replacing the characters denoted by the half-open
* range [`first`,`last`) within this string with the first `M-1`
* characters from the character array `that`.
* \pre `strlen(that) == M-1`
* \note Equivalent to
* <tt>creplace(first - data(), last - first, that, 0, M-1)</tt>
*/
template <std::size_t M>
constexpr BasicFixedString<Char, N + M - 1u> creplace(
const Char* first, const Char* last, const Char (&that)[M]) const
noexcept(false) {
return creplace(first - data_, last - first, that, 0u, M - 1u);
}
/**
* Construct a new string by replacing the characters denoted by the half-open
* range [`first`,`last`) within this string with the `that_count`
* characters from the character array `that` starting at position
* `that_pos`.
* \pre `strlen(that) == M-1`
* \note Equivalent to
* `creplace(first - data(), last - first, that, that_pos, that_count)`
*/
template <std::size_t M>
constexpr BasicFixedString<Char, N + M - 1u> creplace(
const Char* first,
const Char* last,
const Char (&that)[M],
std::size_t that_pos,
std::size_t that_count) const noexcept(false) {
return creplace(first - data_, last - first, that, that_pos, that_count);
}
/**
* Copies `min(count, size())` characters starting from offset `0`
* from this string into the buffer pointed to by `dest`.
* \return The number of characters copied.
*/
constexpr std::size_t copy(Char* dest, std::size_t count) const noexcept {
return copy(dest, count, 0u);
}
/**
* Copies `min(count, size() - pos)` characters starting from offset `pos`
* from this string into the buffer pointed to by `dest`.
* \pre `pos <= size()`
* \return The number of characters copied.
* \throw std::out_of_range if `pos > size()`
*/
constexpr std::size_t copy(
Char* dest, std::size_t count, std::size_t pos) const noexcept(false) {
detail::fixedstring::checkOverflow(pos, size_);
for (std::size_t i = 0u; i < count; ++i) {
if (i + pos == size_) {
return size_;
}
dest[i] = data_[i + pos];
}
return count;
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Resizes the current string.
* \note Equivalent to `resize(count, Char(0))`
*/
constexpr void resize(std::size_t count) noexcept(false) {
resize(count, Char(0));
}
/**
* Resizes the current string by setting the size to `count` and setting
* `data()[count]` to `Char(0)`. If `count > old_size`, the characters
* in the range [`old_size`,`count`) are set to `ch`.
*/
constexpr void resize(std::size_t count, Char ch) noexcept(false) {
detail::fixedstring::checkOverflow(count, N);
if (count == size_) {
} else if (count < size_) {
size_ = count;
data_[size_] = Char(0);
} else {
for (; size_ < count; ++size_) {
data_[size_] = ch;
}
data_[size_] = Char(0);
}
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Finds the first occurrence of the character sequence `that` in this string.
* \note Equivalent to `find(that.data(), 0, that.size())`
*/
template <std::size_t M>
constexpr std::size_t find(
const BasicFixedString<Char, M>& that) const noexcept {
return find(that, 0u);
}
/**
* Finds the first occurrence of the character sequence `that` in this string,
* starting at offset `pos`.
* \pre `pos <= size()`
* \note Equivalent to `find(that.data(), pos, that.size())`
*/
template <std::size_t M>
constexpr std::size_t find(
const BasicFixedString<Char, M>& that, std::size_t pos) const
noexcept(false) {
return that.size_ <= size_ - detail::fixedstring::checkOverflow(pos, size_)
? detail::fixedstring::find_(data_, size_, that.data_, pos, that.size_)
: npos;
}
/**
* Finds the first occurrence of the character sequence `that` in this string.
* \note Equivalent to `find(that.data(), 0, strlen(that))`
*/
constexpr std::size_t find(const Char* that) const noexcept {
return find(that, 0u, folly::constexpr_strlen(that));
}
/**
* Finds the first occurrence of the character sequence `that` in this string,
* starting at offset `pos`.
* \pre `pos <= size()`
* \note Equivalent to `find(that.data(), pos, strlen(that))`
*/
constexpr std::size_t find(const Char* that, std::size_t pos) const
noexcept(false) {
return find(that, pos, folly::constexpr_strlen(that));
}
/**
* Finds the first occurrence of the first `count` characters in the buffer
* pointed to by `that` in this string, starting at offset `pos`.
* \pre `pos <= size()`
* \pre `that` points to a buffer containing at least `count` contiguous
* characters.
* \return The lowest offset `i` such that `i >= pos` and
* `0 == strncmp(data() + i, that, count)`; or `npos` if there is no such
* offset `i`.
* \throw std::out_of_range when `pos > size()`
*/
constexpr std::size_t find(
const Char* that, std::size_t pos, std::size_t count) const
noexcept(false) {
return count <= size_ - detail::fixedstring::checkOverflow(pos, size_)
? detail::fixedstring::find_(data_, size_, that, pos, count)
: npos;
}
/**
* Finds the first occurrence of the character `ch` in this string.
* \note Equivalent to `find(&ch, 0, 1)`
*/
constexpr std::size_t find(Char ch) const noexcept { return find(ch, 0u); }
/**
* Finds the first occurrence of the character character `c` in this string,
* starting at offset `pos`.
* \pre `pos <= size()`
* \note Equivalent to `find(&ch, pos, 1)`
*/
constexpr std::size_t find(Char ch, std::size_t pos) const noexcept(false) {
using A = const Char[1u];
return 0u == size_ - detail::fixedstring::checkOverflow(pos, size_)
? npos
: detail::fixedstring::find_(data_, size_, A{ch}, pos, 1u);
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Finds the last occurrence of characters in the string
* `that` in this string.
* \note Equivalent to `rfind(that.data(), size(), that.size())`
*/
template <std::size_t M>
constexpr std::size_t rfind(
const BasicFixedString<Char, M>& that) const noexcept {
return rfind(that, size_);
}
/**
* Finds the last occurrence of characters in the string
* `that` in this string, starting at offset `pos`.
* \note Equivalent to `rfind(that.data(), pos, that.size())`
*/
template <std::size_t M>
constexpr std::size_t rfind(
const BasicFixedString<Char, M>& that, std::size_t pos) const
noexcept(false) {
return that.size_ <= size_
? detail::fixedstring::rfind_(
data_,
that.data_,
folly::constexpr_min(
detail::fixedstring::checkOverflow(pos, size_),
size_ - that.size_),
that.size_)
: npos;
}
/**
* Finds the last occurrence of characters in the buffer
* pointed to by `that` in this string.
* \note Equivalent to `rfind(that, size(), strlen(that))`
*/
constexpr std::size_t rfind(const Char* that) const noexcept {
return rfind(that, size_, folly::constexpr_strlen(that));
}
/**
* Finds the last occurrence of characters in the buffer
* pointed to by `that` in this string, starting at offset `pos`.
* \note Equivalent to `rfind(that, pos, strlen(that))`
*/
constexpr std::size_t rfind(const Char* that, std::size_t pos) const
noexcept(false) {
return rfind(that, pos, folly::constexpr_strlen(that));
}
/**
* Finds the last occurrence of the first `count` characters in the buffer
* pointed to by `that` in this string, starting at offset `pos`.
* \pre `pos <= size()`
* \pre `that` points to a buffer containing at least `count` contiguous
* characters.
* \return The largest offset `i` such that `i <= pos` and
* `i + count <= size()` and `0 == strncmp(data() + i, that, count)`; or
* `npos` if there is no such offset `i`.
* \throw std::out_of_range when `pos > size()`
*/
constexpr std::size_t rfind(
const Char* that, std::size_t pos, std::size_t count) const
noexcept(false) {
return count <= size_
? detail::fixedstring::rfind_(
data_,
that,
folly::constexpr_min(
detail::fixedstring::checkOverflow(pos, size_),
size_ - count),
count)
: npos;
}
/**
* Finds the last occurrence of the character character `ch` in this string.
* \note Equivalent to `rfind(&ch, size(), 1)`
*/
constexpr std::size_t rfind(Char ch) const noexcept {
return rfind(ch, size_);
}
/**
* Finds the last occurrence of the character character `ch` in this string,
* starting at offset `pos`.
* \pre `pos <= size()`
* \note Equivalent to `rfind(&ch, pos, 1)`
*/
constexpr std::size_t rfind(Char ch, std::size_t pos) const noexcept(false) {
using A = const Char[1u];
return 0u == size_
? npos
: detail::fixedstring::rfind_(
data_,
A{ch},
folly::constexpr_min(
detail::fixedstring::checkOverflow(pos, size_), size_ - 1u),
1u);
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Finds the first occurrence of any character in `that` in this string.
* \note Equivalent to `find_first_of(that.data(), 0, that.size())`
*/
template <std::size_t M>
constexpr std::size_t find_first_of(
const BasicFixedString<Char, M>& that) const noexcept {
return find_first_of(that, 0u);
}
/**
* Finds the first occurrence of any character in `that` in this string,
* starting at offset `pos`
* \note Equivalent to `find_first_of(that.data(), pos, that.size())`
*/
template <std::size_t M>
constexpr std::size_t find_first_of(
const BasicFixedString<Char, M>& that, std::size_t pos) const
noexcept(false) {
return size_ == detail::fixedstring::checkOverflow(pos, size_)
? npos
: detail::fixedstring::find_first_of_(
data_, size_, that.data_, pos, that.size_);
}
/**
* Finds the first occurrence of any character in the null-terminated
* character sequence pointed to by `that` in this string.
* \note Equivalent to `find_first_of(that, 0, strlen(that))`
*/
constexpr std::size_t find_first_of(const Char* that) const noexcept {
return find_first_of(that, 0u, folly::constexpr_strlen(that));
}
/**
* Finds the first occurrence of any character in the null-terminated
* character sequence pointed to by `that` in this string,
* starting at offset `pos`
* \note Equivalent to `find_first_of(that, pos, strlen(that))`
*/
constexpr std::size_t find_first_of(const Char* that, std::size_t pos) const
noexcept(false) {
return find_first_of(that, pos, folly::constexpr_strlen(that));
}
/**
* Finds the first occurrence of any character in the first `count` characters
* in the buffer pointed to by `that` in this string, starting at offset
* `pos`.
* \pre `pos <= size()`
* \pre `that` points to a buffer containing at least `count` contiguous
* characters.
* \return The smallest offset `i` such that `i >= pos` and
* `std::find(that, that+count, at(i)) != that+count`; or
* `npos` if there is no such offset `i`.
* \throw std::out_of_range when `pos > size()`
*/
constexpr std::size_t find_first_of(
const Char* that, std::size_t pos, std::size_t count) const
noexcept(false) {
return size_ == detail::fixedstring::checkOverflow(pos, size_)
? npos
: detail::fixedstring::find_first_of_(data_, size_, that, pos, count);
}
/**
* Finds the first occurrence of `ch` in this string.
* \note Equivalent to `find_first_of(&ch, 0, 1)`
*/
constexpr std::size_t find_first_of(Char ch) const noexcept {
return find_first_of(ch, 0u);
}
/**
* Finds the first occurrence of `ch` in this string,
* starting at offset `pos`.
* \note Equivalent to `find_first_of(&ch, pos, 1)`
*/
constexpr std::size_t find_first_of(Char ch, std::size_t pos) const
noexcept(false) {
using A = const Char[1u];
return size_ == detail::fixedstring::checkOverflow(pos, size_)
? npos
: detail::fixedstring::find_first_of_(data_, size_, A{ch}, pos, 1u);
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Finds the first occurrence of any character not in `that` in this string.
* \note Equivalent to `find_first_not_of(that.data(), 0, that.size())`
*/
template <std::size_t M>
constexpr std::size_t find_first_not_of(
const BasicFixedString<Char, M>& that) const noexcept {
return find_first_not_of(that, 0u);
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Finds the first occurrence of any character not in `that` in this string.
* \note Equivalent to `find_first_not_of(that.data(), 0, that.size())`
*/
template <std::size_t M>
constexpr std::size_t find_first_not_of(
const BasicFixedString<Char, M>& that, std::size_t pos) const
noexcept(false) {
return size_ == detail::fixedstring::checkOverflow(pos, size_)
? npos
: detail::fixedstring::find_first_not_of_(
data_, size_, that.data_, pos, that.size_);
}
/**
* Finds the first occurrence of any character not in the null-terminated
* character sequence pointed to by `that` in this string.
* \note Equivalent to `find_first_not_of(that, 0, strlen(that))`
*/
constexpr std::size_t find_first_not_of(const Char* that) const noexcept {
return find_first_not_of(that, 0u, folly::constexpr_strlen(that));
}
/**
* Finds the first occurrence of any character not in the null-terminated
* character sequence pointed to by `that` in this string,
* starting at offset `pos`
* \note Equivalent to `find_first_not_of(that, pos, strlen(that))`
*/
constexpr std::size_t find_first_not_of(
const Char* that, std::size_t pos) const noexcept(false) {
return find_first_not_of(that, pos, folly::constexpr_strlen(that));
}
/**
* Finds the first occurrence of any character not in the first `count`
* characters in the buffer pointed to by `that` in this string, starting at
* offset `pos`.
* \pre `pos <= size()`
* \pre `that` points to a buffer containing at least `count` contiguous
* characters.
* \return The smallest offset `i` such that `i >= pos` and
* `std::find(that, that+count, at(i)) == that+count`; or
* `npos` if there is no such offset `i`.
* \throw std::out_of_range when `pos > size()`
*/
constexpr std::size_t find_first_not_of(
const Char* that, std::size_t pos, std::size_t count) const
noexcept(false) {
return size_ == detail::fixedstring::checkOverflow(pos, size_)
? npos
: detail::fixedstring::find_first_not_of_(
data_, size_, that, pos, count);
}
/**
* Finds the first occurrence of any character other than `ch` in this string.
* \note Equivalent to `find_first_not_of(&ch, 0, 1)`
*/
constexpr std::size_t find_first_not_of(Char ch) const noexcept {
return find_first_not_of(ch, 0u);
}
/**
* Finds the first occurrence of any character other than `ch` in this string,
* starting at offset `pos`.
* \note Equivalent to `find_first_not_of(&ch, pos, 1)`
*/
constexpr std::size_t find_first_not_of(Char ch, std::size_t pos) const
noexcept(false) {
using A = const Char[1u];
return 1u <= size_ - detail::fixedstring::checkOverflow(pos, size_)
? detail::fixedstring::find_first_not_of_(data_, size_, A{ch}, pos, 1u)
: npos;
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Finds the last occurrence of any character in `that` in this string.
* \note Equivalent to `find_last_of(that.data(), size(), that.size())`
*/
template <std::size_t M>
constexpr std::size_t find_last_of(
const BasicFixedString<Char, M>& that) const noexcept {
return find_last_of(that, size_);
}
/**
* Finds the last occurrence of any character in `that` in this string,
* starting at offset `pos`
* \note Equivalent to `find_last_of(that.data(), pos, that.size())`
*/
template <std::size_t M>
constexpr std::size_t find_last_of(
const BasicFixedString<Char, M>& that, std::size_t pos) const
noexcept(false) {
return 0u == size_
? npos
: detail::fixedstring::find_last_of_(
data_,
that.data_,
folly::constexpr_min(
detail::fixedstring::checkOverflow(pos, size_), size_ - 1u),
that.size_);
}
/**
* Finds the last occurrence of any character in the null-terminated
* character sequence pointed to by `that` in this string.
* \note Equivalent to `find_last_of(that, size(), strlen(that))`
*/
constexpr std::size_t find_last_of(const Char* that) const noexcept {
return find_last_of(that, size_, folly::constexpr_strlen(that));
}
/**
* Finds the last occurrence of any character in the null-terminated
* character sequence pointed to by `that` in this string,
* starting at offset `pos`
* \note Equivalent to `find_last_of(that, pos, strlen(that))`
*/
constexpr std::size_t find_last_of(const Char* that, std::size_t pos) const
noexcept(false) {
return find_last_of(that, pos, folly::constexpr_strlen(that));
}
/**
* Finds the last occurrence of any character in the first `count` characters
* in the buffer pointed to by `that` in this string, starting at offset
* `pos`.
* \pre `pos <= size()`
* \pre `that` points to a buffer containing at least `count` contiguous
* characters.
* \return The largest offset `i` such that `i <= pos` and
* `i < size()` and `std::find(that, that+count, at(i)) != that+count`; or
* `npos` if there is no such offset `i`.
* \throw std::out_of_range when `pos > size()`
*/
constexpr std::size_t find_last_of(
const Char* that, std::size_t pos, std::size_t count) const
noexcept(false) {
return 0u == size_
? npos
: detail::fixedstring::find_last_of_(
data_,
that,
folly::constexpr_min(
detail::fixedstring::checkOverflow(pos, size_), size_ - 1u),
count);
}
/**
* Finds the last occurrence of `ch` in this string.
* \note Equivalent to `find_last_of(&ch, size(), 1)`
*/
constexpr std::size_t find_last_of(Char ch) const noexcept {
return find_last_of(ch, size_);
}
/**
* Finds the last occurrence of `ch` in this string,
* starting at offset `pos`.
* \note Equivalent to `find_last_of(&ch, pos, 1)`
*/
constexpr std::size_t find_last_of(Char ch, std::size_t pos) const
noexcept(false) {
using A = const Char[1u];
return 0u == size_
? npos
: detail::fixedstring::find_last_of_(
data_,
A{ch},
folly::constexpr_min(
detail::fixedstring::checkOverflow(pos, size_), size_ - 1u),
1u);
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Finds the last occurrence of any character not in `that` in this string.
* \note Equivalent to `find_last_not_of(that.data(), size(), that.size())`
*/
template <std::size_t M>
constexpr std::size_t find_last_not_of(
const BasicFixedString<Char, M>& that) const noexcept {
return find_last_not_of(that, size_);
}
/**
* Finds the last occurrence of any character not in `that` in this string,
* starting at offset `pos`
* \note Equivalent to `find_last_not_of(that.data(), pos, that.size())`
*/
template <std::size_t M>
constexpr std::size_t find_last_not_of(
const BasicFixedString<Char, M>& that, std::size_t pos) const
noexcept(false) {
return 0u == size_
? npos
: detail::fixedstring::find_last_not_of_(
data_,
that.data_,
folly::constexpr_min(
detail::fixedstring::checkOverflow(pos, size_), size_ - 1u),
that.size_);
}
/**
* Finds the last occurrence of any character not in the null-terminated
* character sequence pointed to by `that` in this string.
* \note Equivalent to `find_last_not_of(that, size(), strlen(that))`
*/
constexpr std::size_t find_last_not_of(const Char* that) const noexcept {
return find_last_not_of(that, size_, folly::constexpr_strlen(that));
}
/**
* Finds the last occurrence of any character not in the null-terminated
* character sequence pointed to by `that` in this string,
* starting at offset `pos`
* \note Equivalent to `find_last_not_of(that, pos, strlen(that))`
*/
constexpr std::size_t find_last_not_of(
const Char* that, std::size_t pos) const noexcept(false) {
return find_last_not_of(that, pos, folly::constexpr_strlen(that));
}
/**
* Finds the last occurrence of any character not in the first `count`
* characters in the buffer pointed to by `that` in this string, starting at
* offset `pos`.
* \pre `pos <= size()`
* \pre `that` points to a buffer containing at least `count` contiguous
* characters.
* \return The largest offset `i` such that `i <= pos` and
* `i < size()` and `std::find(that, that+count, at(i)) == that+count`; or
* `npos` if there is no such offset `i`.
* \throw std::out_of_range when `pos > size()`
*/
constexpr std::size_t find_last_not_of(
const Char* that, std::size_t pos, std::size_t count) const
noexcept(false) {
return 0u == size_
? npos
: detail::fixedstring::find_last_not_of_(
data_,
that,
folly::constexpr_min(
detail::fixedstring::checkOverflow(pos, size_), size_ - 1u),
count);
}
/**
* Finds the last occurrence of any character other than `ch` in this string.
* \note Equivalent to `find_last_not_of(&ch, size(), 1)`
*/
constexpr std::size_t find_last_not_of(Char ch) const noexcept {
return find_last_not_of(ch, size_);
}
/**
* Finds the last occurrence of any character other than `ch` in this string,
* starting at offset `pos`.
* \note Equivalent to `find_last_not_of(&ch, pos, 1)`
*/
constexpr std::size_t find_last_not_of(Char ch, std::size_t pos) const
noexcept(false) {
using A = const Char[1u];
return 0u == size_
? npos
: detail::fixedstring::find_last_not_of_(
data_,
A{ch},
folly::constexpr_min(
detail::fixedstring::checkOverflow(pos, size_), size_ - 1u),
1u);
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Asymmetric relational operators
*/
friend constexpr bool operator==(
const Char* a, const BasicFixedString& b) noexcept {
return detail::fixedstring::equal_(
a, folly::constexpr_strlen(a), b.data_, b.size_);
}
/**
* \overload
*/
friend constexpr bool operator==(
const BasicFixedString& a, const Char* b) noexcept {
return b == a;
}
/**
* \overload
*/
friend constexpr bool operator==(
Range<const Char*> a, const BasicFixedString& b) noexcept {
return detail::fixedstring::equal_(a.begin(), a.size(), b.data_, b.size_);
}
/**
* \overload
*/
friend constexpr bool operator==(
const BasicFixedString& a, Range<const Char*> b) noexcept {
return b == a;
}
friend constexpr bool operator!=(
const Char* a, const BasicFixedString& b) noexcept {
return !(a == b);
}
/**
* \overload
*/
friend constexpr bool operator!=(
const BasicFixedString& a, const Char* b) noexcept {
return !(b == a);
}
/**
* \overload
*/
friend constexpr bool operator!=(
Range<const Char*> a, const BasicFixedString& b) noexcept {
return !(a == b);
}
/**
* \overload
*/
friend constexpr bool operator!=(
const BasicFixedString& a, Range<const Char*> b) noexcept {
return !(a == b);
}
friend constexpr bool operator<(
const Char* a, const BasicFixedString& b) noexcept {
return ordering::lt ==
detail::fixedstring::compare_(
a, 0u, folly::constexpr_strlen(a), b.data_, 0u, b.size_);
}
/**
* \overload
*/
friend constexpr bool operator<(
const BasicFixedString& a, const Char* b) noexcept {
return ordering::lt ==
detail::fixedstring::compare_(
a.data_, 0u, a.size_, b, 0u, folly::constexpr_strlen(b));
}
/**
* \overload
*/
friend constexpr bool operator<(
Range<const Char*> a, const BasicFixedString& b) noexcept {
return ordering::lt ==
detail::fixedstring::compare_(
a.begin(), 0u, a.size(), b.data_, 0u, b.size_);
}
/**
* \overload
*/
friend constexpr bool operator<(
const BasicFixedString& a, Range<const Char*> b) noexcept {
return ordering::lt ==
detail::fixedstring::compare_(
a.data_, 0u, a.size_, b.begin(), 0u, b.size());
}
friend constexpr bool operator>(
const Char* a, const BasicFixedString& b) noexcept {
return b < a;
}
/**
* \overload
*/
friend constexpr bool operator>(
const BasicFixedString& a, const Char* b) noexcept {
return b < a;
}
/**
* \overload
*/
friend constexpr bool operator>(
Range<const Char*> a, const BasicFixedString& b) noexcept {
return b < a;
}
/**
* \overload
*/
friend constexpr bool operator>(
const BasicFixedString& a, Range<const Char*> b) noexcept {
return b < a;
}
friend constexpr bool operator<=(
const Char* a, const BasicFixedString& b) noexcept {
return !(b < a);
}
/**
* \overload
*/
friend constexpr bool operator<=(
const BasicFixedString& a, const Char* b) noexcept {
return !(b < a);
}
/**
* \overload
*/
friend constexpr bool operator<=(
Range<const Char*> const& a, const BasicFixedString& b) noexcept {
return !(b < a);
}
/**
* \overload
*/
friend constexpr bool operator<=(
const BasicFixedString& a, Range<const Char*> b) noexcept {
return !(b < a);
}
friend constexpr bool operator>=(
const Char* a, const BasicFixedString& b) noexcept {
return !(a < b);
}
/**
* \overload
*/
friend constexpr bool operator>=(
const BasicFixedString& a, const Char* b) noexcept {
return !(a < b);
}
/**
* \overload
*/
friend constexpr bool operator>=(
Range<const Char*> a, const BasicFixedString& b) noexcept {
return !(a < b);
}
/**
* \overload
*/
friend constexpr bool operator>=(
const BasicFixedString& a, Range<const Char*> const& b) noexcept {
return !(a < b);
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Asymmetric concatenation
*/
template <std::size_t M>
friend constexpr BasicFixedString<Char, N + M - 1u> operator+(
const Char (&a)[M], const BasicFixedString& b) noexcept {
return detail::fixedstring::Helper::concat_<Char>(
detail::fixedstring::checkNullTerminated(a),
M - 1u,
b.data_,
b.size_,
std::make_index_sequence<N + M - 1u>{});
}
/**
* \overload
*/
template <std::size_t M>
friend constexpr BasicFixedString<Char, N + M - 1u> operator+(
const BasicFixedString& a, const Char (&b)[M]) noexcept {
return detail::fixedstring::Helper::concat_<Char>(
a.data_,
a.size_,
detail::fixedstring::checkNullTerminated(b),
M - 1u,
std::make_index_sequence<N + M - 1u>{});
}
/**
* \overload
*/
friend constexpr BasicFixedString<Char, N + 1u> operator+(
Char a, const BasicFixedString& b) noexcept {
using A = const Char[2u];
return detail::fixedstring::Helper::concat_<Char>(
A{a, Char(0)},
1u,
b.data_,
b.size_,
std::make_index_sequence<N + 1u>{});
}
/**
* \overload
*/
friend constexpr BasicFixedString<Char, N + 1u> operator+(
const BasicFixedString& a, Char b) noexcept {
using A = const Char[2u];
return detail::fixedstring::Helper::concat_<Char>(
a.data_,
a.size_,
A{b, Char(0)},
1u,
std::make_index_sequence<N + 1u>{});
}
};
template <class C, std::size_t N>
inline std::basic_ostream<C>& operator<<(
std::basic_ostream<C>& os, const BasicFixedString<C, N>& string) {
using StreamSize = decltype(os.width());
os.write(string.begin(), static_cast<StreamSize>(string.size()));
return os;
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Symmetric relational operators
*/
template <class Char, std::size_t A, std::size_t B>
constexpr bool operator==(
const BasicFixedString<Char, A>& a,
const BasicFixedString<Char, B>& b) noexcept {
return detail::fixedstring::equal_(
detail::fixedstring::Helper::data_(a),
a.size(),
detail::fixedstring::Helper::data_(b),
b.size());
}
template <class Char, std::size_t A, std::size_t B>
constexpr bool operator!=(
const BasicFixedString<Char, A>& a, const BasicFixedString<Char, B>& b) {
return !(a == b);
}
template <class Char, std::size_t A, std::size_t B>
constexpr bool operator<(
const BasicFixedString<Char, A>& a,
const BasicFixedString<Char, B>& b) noexcept {
return ordering::lt ==
detail::fixedstring::compare_(
detail::fixedstring::Helper::data_(a),
0u,
a.size(),
detail::fixedstring::Helper::data_(b),
0u,
b.size());
}
template <class Char, std::size_t A, std::size_t B>
constexpr bool operator>(
const BasicFixedString<Char, A>& a,
const BasicFixedString<Char, B>& b) noexcept {
return b < a;
}
template <class Char, std::size_t A, std::size_t B>
constexpr bool operator<=(
const BasicFixedString<Char, A>& a,
const BasicFixedString<Char, B>& b) noexcept {
return !(b < a);
}
template <class Char, std::size_t A, std::size_t B>
constexpr bool operator>=(
const BasicFixedString<Char, A>& a,
const BasicFixedString<Char, B>& b) noexcept {
return !(a < b);
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Symmetric concatenation
*/
template <class Char, std::size_t N, std::size_t M>
constexpr BasicFixedString<Char, N + M> operator+(
const BasicFixedString<Char, N>& a,
const BasicFixedString<Char, M>& b) noexcept {
return detail::fixedstring::Helper::concat_<Char>(
detail::fixedstring::Helper::data_(a),
a.size(),
detail::fixedstring::Helper::data_(b),
b.size(),
std::make_index_sequence<N + M>{});
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Construct a `BasicFixedString` object from a null-terminated array of
* characters. The capacity and size of the string will be equal to one less
* than the size of the array.
* \pre `a` contains no embedded null characters.
* \pre `a[N-1] == Char(0)`
* \post For a returned string `s`, `s[i]==a[i]` for every `i` in [`0`,`N-1`].
*/
template <class Char, std::size_t N>
constexpr BasicFixedString<Char, N - 1u> makeFixedString(
const Char (&a)[N]) noexcept {
return {a};
}
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** **
* Swap function
*/
template <class Char, std::size_t N>
constexpr void swap(
BasicFixedString<Char, N>& a, BasicFixedString<Char, N>& b) noexcept {
a.swap(b);
}
inline namespace literals {
inline namespace string_literals {
inline namespace {
// "const std::size_t&" is so that folly::npos has the same address in every
// translation unit. This is to avoid potential violations of the ODR.
constexpr const std::size_t& npos = detail::fixedstring::FixedStringBase::npos;
} // namespace
#if defined(__GNUC__) && !defined(__ICC)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wpragmas"
#pragma GCC diagnostic ignored "-Wgnu-string-literal-operator-template"
/** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** ** *
* User-defined literals for creating FixedString objects from string literals
* on the compilers that support it.
*
* \par Example:
* \par
* \code
* using namespace folly::string_literals;
* constexpr auto hello = "hello world!"_fs;
* \endcode
*
* \note This requires a GNU compiler extension
* (-Wgnu-string-literal-operator-template) supported by clang and gcc,
* proposed for standardization in
* <http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0424r0.pdf>.
* \par
* For portable code, prefer the suffixes `_fs4`, `_fs8`, `_fs16`, `_fs32`,
* `_fs64`, and `_fs128` for creating instances of types `FixedString<4>`,
* `FixedString<8>`, `FixedString<16>`, etc.
*/
template <class Char, Char... Cs>
constexpr BasicFixedString<Char, sizeof...(Cs)> operator""_fs() noexcept {
const Char a[] = {Cs..., Char(0)};
return {+a, sizeof...(Cs)};
}
#pragma GCC diagnostic pop
#endif
#ifndef NO_FIXED_STR_UDL
#define FOLLY_DEFINE_FIXED_STRING_UDL(N) \
constexpr FixedString<N> operator""_fs##N( \
const char* that, std::size_t count) noexcept(false) { \
return {that, count}; \
} \
/**/
// Define UDLs _fs4, _fs8, _fs16, etc for FixedString<[4, 8, 16, ...]>
FOLLY_DEFINE_FIXED_STRING_UDL(4)
FOLLY_DEFINE_FIXED_STRING_UDL(8)
FOLLY_DEFINE_FIXED_STRING_UDL(16)
FOLLY_DEFINE_FIXED_STRING_UDL(32)
FOLLY_DEFINE_FIXED_STRING_UDL(64)
FOLLY_DEFINE_FIXED_STRING_UDL(128)
#undef FOLLY_DEFINE_FIXED_STRING_UDL
#endif
} // namespace string_literals
} // namespace literals
// TODO:
// // numeric conversions:
// template <std::size_t N>
// constexpr int stoi(const FixedString<N>& str, int base = 10);
// template <std::size_t N>
// constexpr unsigned stou(const FixedString<N>& str, int base = 10);
// template <std::size_t N>
// constexpr long stol(const FixedString<N>& str, int base = 10);
// template <std::size_t N>
// constexpr unsigned long stoul(const FixedString<N>& str, int base = 10;
// template <std::size_t N>
// constexpr long long stoll(const FixedString<N>& str, int base = 10);
// template <std::size_t N>
// constexpr unsigned long long stoull(const FixedString<N>& str,
// int base = 10);
// template <std::size_t N>
// constexpr float stof(const FixedString<N>& str);
// template <std::size_t N>
// constexpr double stod(const FixedString<N>& str);
// template <std::size_t N>
// constexpr long double stold(const FixedString<N>& str);
// template <int val>
// constexpr FixedString</*...*/> to_fixed_string_i() noexcept;
// template <unsigned val>
// constexpr FixedString</*...*/> to_fixed_string_u() noexcept;
// template <long val>
// constexpr FixedString</*...*/> to_fixed_string_l() noexcept;
// template <unsigned long val>
// constexpr FixedString</*...*/> to_fixed_string_ul() noexcept;
// template <long long val>
// constexpr FixedString</*...*/> to_fixed_string_ll() noexcept
// template <unsigned long long val>
// constexpr FixedString</*...*/> to_fixed_string_ull() noexcept;
} // namespace folly
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