//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14, c++17
// <algorithm>
// template<input_iterator I, sentinel_for<I> S, class T, output_iterator<const T&> O,
// class Proj = identity, indirect_unary_predicate<projected<I, Proj>> Pred>
// requires indirectly_copyable<I, O>
// constexpr replace_copy_if_result<I, O>
// replace_copy_if(I first, S last, O result, Pred pred, const T& new_value,
// Proj proj = {}); // Since C++20
//
// template<input_range R, class T, output_iterator<const T&> O, class Proj = identity,
// indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
// requires indirectly_copyable<iterator_t<R>, O>
// constexpr replace_copy_if_result<borrowed_iterator_t<R>, O>
// replace_copy_if(R&& r, O result, Pred pred, const T& new_value,
// Proj proj = {}); // Since C++20
#include <algorithm>
#include <array>
#include <concepts>
#include <functional>
#include <ranges>
#include <utility>
#include "almost_satisfies_types.h"
#include "counting_predicates.h"
#include "counting_projection.h"
#include "test_iterators.h"
struct FalsePredicate {
constexpr bool operator()(int) { return false; }
};
template <class Iter, class Sent = sentinel_wrapper<Iter>, class OutIter = int*>
concept HasReplaceCopyIfIter = requires(Iter&& first, Sent&& last, OutIter&& result) {
std::ranges::replace_copy_if(
std::forward<Iter>(first), std::forward<Sent>(last), std::forward<OutIter>(result), FalsePredicate{}, 0);
};
static_assert(HasReplaceCopyIfIter<int*>);
// !input_iterator<I>
static_assert(!HasReplaceCopyIfIter<InputIteratorNotDerivedFrom>);
static_assert(!HasReplaceCopyIfIter<InputIteratorNotIndirectlyReadable>);
static_assert(!HasReplaceCopyIfIter<InputIteratorNotInputOrOutputIterator>);
// !sentinel_for<S, I>
static_assert(!HasReplaceCopyIfIter<int*, SentinelForNotSemiregular>);
static_assert(!HasReplaceCopyIfIter<int*, SentinelForNotWeaklyEqualityComparableWith>);
// !output_iterator<O, const T2&>
static_assert(!HasReplaceCopyIfIter<int*, int*, OutputIteratorNotIndirectlyWritable>);
static_assert(!HasReplaceCopyIfIter<int*, int*, OutputIteratorNotInputOrOutputIterator>);
// !indirect_unary_predicate<Pred, projected<I, Proj>> Pred>
static_assert(!HasReplaceCopyIfIter<IndirectUnaryPredicateNotCopyConstructible>);
static_assert(!HasReplaceCopyIfIter<IndirectUnaryPredicateNotPredicate>);
// !indirectly_copyable<I, O>
static_assert(!HasReplaceCopyIfIter<int*, int*, int**>);
template <class Range, class OutIter = int*>
concept HasReplaceCopyIfRange = requires(Range&& range, OutIter&& result) {
std::ranges::replace_copy_if(std::forward<Range>(range), std::forward<OutIter>(result), FalsePredicate{}, 0);
};
template <class T>
using R = UncheckedRange<T>;
static_assert(HasReplaceCopyIfRange<R<int*>>);
// !input_range<R>
static_assert(!HasReplaceCopyIfRange<InputRangeNotDerivedFrom>);
static_assert(!HasReplaceCopyIfRange<InputRangeNotIndirectlyReadable>);
static_assert(!HasReplaceCopyIfRange<InputRangeNotInputOrOutputIterator>);
static_assert(!HasReplaceCopyIfRange<InputRangeNotSentinelSemiregular>);
static_assert(!HasReplaceCopyIfRange<InputRangeNotSentinelEqualityComparableWith>);
// !output_iterator<O, const T2&>
static_assert(!HasReplaceCopyIfRange<R<int*>, OutputIteratorNotIndirectlyWritable>);
static_assert(!HasReplaceCopyIfRange<R<int*>, OutputIteratorNotInputOrOutputIterator>);
// !indirect_unary_predicate<Pred, projected<iterator_t<R>, Proj>> Pred>
static_assert(!HasReplaceCopyIfRange<R<IndirectUnaryPredicateNotPredicate>>);
// !indirectly_copyable<iterator_t<R>, O>
static_assert(!HasReplaceCopyIfRange<R<int*>, int**>);
template <int N>
struct Data {
std::array<int, N> input;
int cutoff;
int new_value;
std::array<int, N> expected;
};
template <class InIter, class Sent, class OutIter, int N>
constexpr void test(Data<N> d) {
{ // iterator overload
std::array<int, N> output;
auto first = InIter(d.input.data());
auto last = Sent(InIter(d.input.data() + d.input.size()));
auto result = OutIter(output.data());
auto pred = [&](int i) { return i < d.cutoff; };
std::same_as<std::ranges::replace_copy_if_result<InIter, OutIter>> decltype(auto) ret =
std::ranges::replace_copy_if(std::move(first), std::move(last), std::move(result), pred, d.new_value);
assert(base(ret.in) == d.input.data() + d.input.size());
assert(base(ret.out) == output.data() + output.size());
assert(d.expected == output);
}
{ // range overload
std::array<int, N> output;
auto range = std::ranges::subrange(InIter(d.input.data()), Sent(InIter(d.input.data() + d.input.size())));
auto result = OutIter(output.data());
auto pred = [&](int i) { return i < d.cutoff; };
std::same_as<std::ranges::replace_copy_if_result<InIter, OutIter>> decltype(auto) ret =
std::ranges::replace_copy_if(range, result, pred, d.new_value);
assert(base(ret.in) == d.input.data() + d.input.size());
assert(base(ret.out) == output.data() + output.size());
assert(d.expected == output);
}
}
template <class InIter, class Sent, class OutIter>
constexpr void tests() {
// simple test
test<InIter, Sent, OutIter, 4>({.input = {1, 2, 3, 4}, .cutoff = 2, .new_value = 5, .expected = {5, 2, 3, 4}});
// empty range
test<InIter, Sent, OutIter, 0>({.input = {}, .cutoff = 2, .new_value = 5, .expected = {}});
// all elements match
test<InIter, Sent, OutIter, 4>({.input = {1, 1, 1, 1}, .cutoff = 2, .new_value = 2, .expected = {2, 2, 2, 2}});
// no element matches
test<InIter, Sent, OutIter, 4>({.input = {1, 1, 1, 1}, .cutoff = 1, .new_value = 3, .expected = {1, 1, 1, 1}});
// more elements
test<InIter, Sent, OutIter, 7>(
{.input = {1, 2, 3, 4, 5, 6, 7}, .cutoff = 3, .new_value = 3, .expected = {3, 3, 3, 4, 5, 6, 7}});
// single element - match
test<InIter, Sent, OutIter, 1>({.input = {1}, .cutoff = 2, .new_value = 5, .expected = {5}});
// single element - no match
test<InIter, Sent, OutIter, 1>({.input = {2}, .cutoff = 2, .new_value = 5, .expected = {2}});
}
template <class InIter, class Sent>
constexpr void test_output_iterators() {
tests<InIter, Sent, cpp17_output_iterator<int*>>();
tests<InIter, Sent, forward_iterator<int*>>();
tests<InIter, Sent, bidirectional_iterator<int*>>();
tests<InIter, Sent, random_access_iterator<int*>>();
tests<InIter, Sent, contiguous_iterator<int*>>();
tests<InIter, Sent, int*>();
}
template <class InIter>
constexpr void test_sentinels() {
test_output_iterators<InIter, InIter>();
test_output_iterators<InIter, sentinel_wrapper<InIter>>();
test_output_iterators<InIter, sized_sentinel<InIter>>();
}
constexpr bool test() {
test_output_iterators<cpp17_input_iterator<int*>, sentinel_wrapper<cpp17_input_iterator<int*>>>();
test_output_iterators<cpp20_input_iterator<int*>, sentinel_wrapper<cpp20_input_iterator<int*>>>();
test_sentinels<forward_iterator<int*>>();
test_sentinels<bidirectional_iterator<int*>>();
test_sentinels<random_access_iterator<int*>>();
test_sentinels<contiguous_iterator<int*>>();
test_sentinels<int*>();
test_sentinels<const int*>();
{ // check that a custom projection works
struct S {
int i;
};
{ // iterator overload
S a[] = {{1}, {2}, {3}, {4}};
S b[4];
auto ret = std::ranges::replace_copy_if(std::begin(a), std::end(a), std::begin(b), FalsePredicate{}, S{2}, &S::i);
assert(ret.in == std::end(a));
assert(ret.out == std::end(b));
assert(std::ranges::equal(a, b, {}, &S::i, &S::i));
}
{ // range overload
S a[] = {{1}, {2}, {3}, {4}};
S b[4];
auto ret = std::ranges::replace_copy_if(a, std::begin(b), FalsePredicate{}, S{2}, &S::i);
assert(ret.in == std::end(a));
assert(ret.out == std::end(b));
assert(std::ranges::equal(a, b, {}, &S::i, &S::i));
}
}
{ // Complexity: exactly `last - first` applications of the corresponding predicate and any projection.
{ // iterator overload
int pred_count = 0;
int proj_count = 0;
int a[] = {1, 2, 3, 4};
int b[4];
std::ranges::replace_copy_if(
std::begin(a), std::end(a), std::begin(b),
counting_predicate(FalsePredicate{}, pred_count), 0, counting_projection(proj_count));
assert(pred_count == 4);
assert(proj_count == 4);
}
{ // range overload
int pred_count = 0;
int proj_count = 0;
int a[] = {1, 2, 3, 4};
int b[4];
std::ranges::replace_copy_if(a, std::begin(b),
counting_predicate(FalsePredicate{}, pred_count), 0, counting_projection(proj_count));
assert(pred_count == 4);
assert(proj_count == 4);
}
}
{ // using different types for the old and new values works
struct S {
constexpr operator int() const { return 1; }
};
{
int a[] = {0, 0, 2, 3};
int b[4];
std::ranges::replace_copy_if(std::begin(a), std::end(a), std::begin(b), [](int i) { return i < 2; }, S{});
assert(std::ranges::equal(b, std::array{1, 1, 2, 3}));
}
{
int a[] = {0, 0, 2, 3};
int b[4];
std::ranges::replace_copy_if(a, std::begin(b), [](int i) { return i < 2; }, S{});
assert(std::ranges::equal(b, std::array{1, 1, 2, 3}));
}
}
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}
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