// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___FORMAT_FORMAT_ARG_STORE_H
#define _LIBCPP___FORMAT_FORMAT_ARG_STORE_H
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
#include <__concepts/arithmetic.h>
#include <__concepts/same_as.h>
#include <__config>
#include <__format/concepts.h>
#include <__format/format_arg.h>
#include <__type_traits/conditional.h>
#include <__type_traits/extent.h>
#include <__type_traits/remove_const.h>
#include <cstdint>
#include <string>
#include <string_view>
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER >= 20
namespace __format {
/// \returns The @c __arg_t based on the type of the formatting argument.
///
/// \pre \c __formattable<_Tp, typename _Context::char_type>
template <class _Context, class _Tp>
consteval __arg_t __determine_arg_t();
// Boolean
template <class, same_as<bool> _Tp>
consteval __arg_t __determine_arg_t() {
return __arg_t::__boolean;
}
// Char
template <class _Context, same_as<typename _Context::char_type> _Tp>
consteval __arg_t __determine_arg_t() {
return __arg_t::__char_type;
}
# ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
template <class _Context, class _CharT>
requires(same_as<typename _Context::char_type, wchar_t> && same_as<_CharT, char>)
consteval __arg_t __determine_arg_t() {
return __arg_t::__char_type;
}
# endif
// Signed integers
template <class, __libcpp_signed_integer _Tp>
consteval __arg_t __determine_arg_t() {
if constexpr (sizeof(_Tp) <= sizeof(int))
return __arg_t::__int;
else if constexpr (sizeof(_Tp) <= sizeof(long long))
return __arg_t::__long_long;
# ifndef _LIBCPP_HAS_NO_INT128
else if constexpr (sizeof(_Tp) == sizeof(__int128_t))
return __arg_t::__i128;
# endif
else
static_assert(sizeof(_Tp) == 0, "an unsupported signed integer was used");
}
// Unsigned integers
template <class, __libcpp_unsigned_integer _Tp>
consteval __arg_t __determine_arg_t() {
if constexpr (sizeof(_Tp) <= sizeof(unsigned))
return __arg_t::__unsigned;
else if constexpr (sizeof(_Tp) <= sizeof(unsigned long long))
return __arg_t::__unsigned_long_long;
# ifndef _LIBCPP_HAS_NO_INT128
else if constexpr (sizeof(_Tp) == sizeof(__uint128_t))
return __arg_t::__u128;
# endif
else
static_assert(sizeof(_Tp) == 0, "an unsupported unsigned integer was used");
}
// Floating-point
template <class, same_as<float> _Tp>
consteval __arg_t __determine_arg_t() {
return __arg_t::__float;
}
template <class, same_as<double> _Tp>
consteval __arg_t __determine_arg_t() {
return __arg_t::__double;
}
template <class, same_as<long double> _Tp>
consteval __arg_t __determine_arg_t() {
return __arg_t::__long_double;
}
// Char pointer
template <class _Context, class _Tp>
requires(same_as<typename _Context::char_type*, _Tp> || same_as<const typename _Context::char_type*, _Tp>)
consteval __arg_t __determine_arg_t() {
return __arg_t::__const_char_type_ptr;
}
// Char array
template <class _Context, class _Tp>
requires(is_array_v<_Tp> && same_as<_Tp, typename _Context::char_type[extent_v<_Tp>]>)
consteval __arg_t __determine_arg_t() {
return __arg_t::__string_view;
}
// String view
template <class _Context, class _Tp>
requires(same_as<typename _Context::char_type, typename _Tp::value_type> &&
same_as<_Tp, basic_string_view<typename _Tp::value_type, typename _Tp::traits_type>>)
consteval __arg_t __determine_arg_t() {
return __arg_t::__string_view;
}
// String
template <class _Context, class _Tp>
requires(
same_as<typename _Context::char_type, typename _Tp::value_type> &&
same_as<_Tp, basic_string<typename _Tp::value_type, typename _Tp::traits_type, typename _Tp::allocator_type>>)
consteval __arg_t __determine_arg_t() {
return __arg_t::__string_view;
}
// Pointers
template <class, class _Ptr>
requires(same_as<_Ptr, void*> || same_as<_Ptr, const void*> || same_as<_Ptr, nullptr_t>)
consteval __arg_t __determine_arg_t() {
return __arg_t::__ptr;
}
// Handle
//
// Note this version can't be constrained avoiding ambiguous overloads.
// That means it can be instantiated by disabled formatters. To solve this, a
// constrained version for not formattable formatters is added.
template <class _Context, class _Tp>
consteval __arg_t __determine_arg_t() {
return __arg_t::__handle;
}
// The overload for not formattable types allows triggering the static
// assertion below.
template <class _Context, class _Tp>
requires(!__formattable_with<_Tp, _Context>)
consteval __arg_t __determine_arg_t() {
return __arg_t::__none;
}
// Pseudo constuctor for basic_format_arg
//
// Modeled after template<class T> explicit basic_format_arg(T& v) noexcept;
// [format.arg]/4-6
template <class _Context, class _Tp>
_LIBCPP_HIDE_FROM_ABI basic_format_arg<_Context> __create_format_arg(_Tp& __value) noexcept {
using _Dp = remove_const_t<_Tp>;
constexpr __arg_t __arg = __determine_arg_t<_Context, _Dp>();
static_assert(__arg != __arg_t::__none, "the supplied type is not formattable");
static_assert(__formattable_with<_Tp, _Context>);
// Not all types can be used to directly initialize the
// __basic_format_arg_value. First handle all types needing adjustment, the
// final else requires no adjustment.
if constexpr (__arg == __arg_t::__char_type)
# ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
if constexpr (same_as<typename _Context::char_type, wchar_t> && same_as<_Dp, char>)
return basic_format_arg<_Context>{__arg, static_cast<wchar_t>(static_cast<unsigned char>(__value))};
else
# endif
return basic_format_arg<_Context>{__arg, __value};
else if constexpr (__arg == __arg_t::__int)
return basic_format_arg<_Context>{__arg, static_cast<int>(__value)};
else if constexpr (__arg == __arg_t::__long_long)
return basic_format_arg<_Context>{__arg, static_cast<long long>(__value)};
else if constexpr (__arg == __arg_t::__unsigned)
return basic_format_arg<_Context>{__arg, static_cast<unsigned>(__value)};
else if constexpr (__arg == __arg_t::__unsigned_long_long)
return basic_format_arg<_Context>{__arg, static_cast<unsigned long long>(__value)};
else if constexpr (__arg == __arg_t::__string_view)
// Using std::size on a character array will add the NUL-terminator to the size.
if constexpr (is_array_v<_Dp>)
return basic_format_arg<_Context>{
__arg, basic_string_view<typename _Context::char_type>{__value, extent_v<_Dp> - 1}};
else
// When the _Traits or _Allocator are different an implicit conversion will
// fail.
return basic_format_arg<_Context>{
__arg, basic_string_view<typename _Context::char_type>{__value.data(), __value.size()}};
else if constexpr (__arg == __arg_t::__ptr)
return basic_format_arg<_Context>{__arg, static_cast<const void*>(__value)};
else if constexpr (__arg == __arg_t::__handle)
return basic_format_arg<_Context>{__arg, typename __basic_format_arg_value<_Context>::__handle{__value}};
else
return basic_format_arg<_Context>{__arg, __value};
}
template <class _Context, class... _Args>
_LIBCPP_HIDE_FROM_ABI void
__create_packed_storage(uint64_t& __types, __basic_format_arg_value<_Context>* __values, _Args&... __args) noexcept {
int __shift = 0;
(
[&] {
basic_format_arg<_Context> __arg = __format::__create_format_arg<_Context>(__args);
if (__shift != 0)
__types |= static_cast<uint64_t>(__arg.__type_) << __shift;
else
// Assigns the initial value.
__types = static_cast<uint64_t>(__arg.__type_);
__shift += __packed_arg_t_bits;
*__values++ = __arg.__value_;
}(),
...);
}
template <class _Context, class... _Args>
_LIBCPP_HIDE_FROM_ABI void __store_basic_format_arg(basic_format_arg<_Context>* __data, _Args&... __args) noexcept {
([&] { *__data++ = __format::__create_format_arg<_Context>(__args); }(), ...);
}
template <class _Context, size_t _Np>
struct __packed_format_arg_store {
__basic_format_arg_value<_Context> __values_[_Np];
uint64_t __types_ = 0;
};
template <class _Context>
struct __packed_format_arg_store<_Context, 0> {
uint64_t __types_ = 0;
};
template <class _Context, size_t _Np>
struct __unpacked_format_arg_store {
basic_format_arg<_Context> __args_[_Np];
};
} // namespace __format
template <class _Context, class... _Args>
struct _LIBCPP_TEMPLATE_VIS __format_arg_store {
_LIBCPP_HIDE_FROM_ABI __format_arg_store(_Args&... __args) noexcept {
if constexpr (sizeof...(_Args) != 0) {
if constexpr (__format::__use_packed_format_arg_store(sizeof...(_Args)))
__format::__create_packed_storage(__storage.__types_, __storage.__values_, __args...);
else
__format::__store_basic_format_arg<_Context>(__storage.__args_, __args...);
}
}
using _Storage =
conditional_t<__format::__use_packed_format_arg_store(sizeof...(_Args)),
__format::__packed_format_arg_store<_Context, sizeof...(_Args)>,
__format::__unpacked_format_arg_store<_Context, sizeof...(_Args)>>;
_Storage __storage;
};
#endif // _LIBCPP_STD_VER >= 20
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___FORMAT_FORMAT_ARG_STORE_H
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