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//===----------------------------------------------------------------------===//
//
// 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
// <iterator>
//
// template <class C> constexpr auto begin(C& c) -> decltype(c.begin()); // constexpr since C++17
// template <class C> constexpr auto begin(const C& c) -> decltype(c.begin()); // constexpr since C++17
// template <class C> constexpr auto end(C& c) -> decltype(c.end()); // constexpr since C++17
// template <class C> constexpr auto end(const C& c) -> decltype(c.end()); // constexpr since C++17
//
// template <class C> constexpr auto cbegin(const C& c) noexcept(see-below) -> decltype(std::begin(c)); // C++14
// template <class C> constexpr auto cend(const C& c) noexcept(see-below) -> decltype(std::end(c)); // C++14
// template <class C> constexpr auto rbegin(C& c) -> decltype(c.rbegin()); // C++14, constexpr since C++17
// template <class C> constexpr auto rbegin(const C& c) -> decltype(c.rbegin()); // C++14, constexpr since C++17
// template <class C> constexpr auto rend(C& c) -> decltype(c.rend()); // C++14, constexpr since C++17
// template <class C> constexpr auto rend(const C& c) -> decltype(c.rend()); // C++14, constexpr since C++17
// template <class C> constexpr auto crbegin(const C& c) -> decltype(std::rbegin(c)); // C++14, constexpr since C++17
// template <class C> constexpr auto crend(const C& c) -> decltype(std::rend(c)); // C++14, constexpr since C++17
#include <array>
#include <cassert>
#include <iterator>
#include <list>
#include <vector>
#include "test_macros.h"
template <typename C,
typename Iterator = typename C::iterator,
typename ConstIterator = typename C::const_iterator,
typename ReverseIterator = typename C::reverse_iterator,
typename ConstReverseIterator = typename C::const_reverse_iterator>
TEST_CONSTEXPR_CXX17 bool test() {
C c = {1, 2, 3};
const C& cc = c;
// std::begin(C& c) / std::end(C& c)
{
ASSERT_SAME_TYPE(decltype(std::begin(c)), Iterator);
assert(std::begin(c) == c.begin());
ASSERT_SAME_TYPE(decltype(std::end(c)), Iterator);
assert(std::end(c) == c.end());
}
// std::begin(C const& c) / std::end(C const& c)
{
ASSERT_SAME_TYPE(decltype(std::begin(cc)), ConstIterator);
assert(std::begin(cc) == cc.begin());
ASSERT_SAME_TYPE(decltype(std::end(cc)), ConstIterator);
assert(std::end(cc) == cc.end());
}
#if TEST_STD_VER >= 14
// std::cbegin(C const&) / std::cend(C const&)
{
ASSERT_SAME_TYPE(decltype(std::cbegin(cc)), ConstIterator);
static_assert(noexcept(std::cbegin(cc)) == noexcept(std::begin(cc)), "");
assert(std::cbegin(cc) == std::begin(cc));
ASSERT_SAME_TYPE(decltype(std::cend(cc)), ConstIterator);
static_assert(noexcept(std::cend(cc)) == noexcept(std::end(cc)), "");
assert(std::cend(cc) == std::end(cc));
// kind of overkill, but whatever
ASSERT_SAME_TYPE(decltype(std::cbegin(c)), ConstIterator);
static_assert(noexcept(std::cbegin(c)) == noexcept(std::begin(cc)), "");
assert(std::cbegin(c) == std::begin(cc));
ASSERT_SAME_TYPE(decltype(std::cend(c)), ConstIterator);
static_assert(noexcept(std::cend(c)) == noexcept(std::end(cc)), "");
assert(std::cend(c) == std::end(cc));
}
// std::rbegin(C& c) / std::rend(C& c)
{
ASSERT_SAME_TYPE(decltype(std::rbegin(c)), ReverseIterator);
assert(std::rbegin(c) == c.rbegin());
ASSERT_SAME_TYPE(decltype(std::rend(c)), ReverseIterator);
assert(std::rend(c) == c.rend());
}
// std::rbegin(C const&) / std::rend(C const&)
{
ASSERT_SAME_TYPE(decltype(std::rbegin(cc)), ConstReverseIterator);
assert(std::rbegin(cc) == cc.rbegin());
ASSERT_SAME_TYPE(decltype(std::rend(cc)), ConstReverseIterator);
assert(std::rend(cc) == cc.rend());
}
// std::crbegin(C const&) / std::crend(C const&)
{
ASSERT_SAME_TYPE(decltype(std::crbegin(cc)), ConstReverseIterator);
assert(std::crbegin(cc) == std::rbegin(cc));
ASSERT_SAME_TYPE(decltype(std::crend(cc)), ConstReverseIterator);
assert(std::crend(cc) == std::rend(cc));
// kind of overkill, but whatever
ASSERT_SAME_TYPE(decltype(std::crbegin(c)), ConstReverseIterator);
assert(std::crbegin(c) == std::rbegin(cc));
ASSERT_SAME_TYPE(decltype(std::crend(c)), ConstReverseIterator);
assert(std::crend(c) == std::rend(cc));
}
#endif // TEST_STD_VER >= 14
return true;
}
int main(int, char**) {
test<std::array<int, 3>>();
test<std::list<int>>();
test<std::vector<int>>();
#if TEST_STD_VER >= 17
static_assert(test<std::array<int, 3>>());
#endif
// Note: Properly testing the conditional noexcept-ness propagation in std::cbegin and std::cend
// requires using C-style arrays, because those are the only ones with a noexcept std::begin
// and std::end inside namespace std
#if TEST_STD_VER >= 14
{
int a[] = {1, 2, 3};
auto const& ca = a;
ASSERT_NOEXCEPT(std::cbegin(ca));
ASSERT_NOEXCEPT(std::cend(ca));
// kind of overkill, but whatever
ASSERT_NOEXCEPT(std::cbegin(a));
ASSERT_NOEXCEPT(std::cend(a));
}
// Make sure std::cbegin and std::cend are constexpr in C++14 too (see LWG2280).
{
static constexpr int a[] = {1, 2, 3};
constexpr auto b = std::cbegin(a);
assert(b == a);
constexpr auto e = std::cend(a);
assert(e == a + 3);
}
#endif
return 0;
}
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