96a509bca2
implement `std::ranges::basic_istream_view` and `std::views::istream`. Although the view itself is constexpr, the constructor argument is a base class std::istream where its ctor/dtor are not constexpr. So no tests are performed in constexpr Differential Revision: https://reviews.llvm.org/D133317
59 lines
1.5 KiB
C++
59 lines
1.5 KiB
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
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
// UNSUPPORTED: no-localization
|
|
// UNSUPPORTED: c++03, c++11, c++14, c++17
|
|
|
|
// constexpr auto begin();
|
|
|
|
#include <cassert>
|
|
#include <ranges>
|
|
#include <sstream>
|
|
|
|
#include "test_macros.h"
|
|
#include "utils.h"
|
|
|
|
template <class T>
|
|
concept HasBegin = requires(T t) { t.begin(); };
|
|
|
|
static_assert(HasBegin<std::ranges::istream_view<int>>);
|
|
static_assert(!HasBegin<const std::ranges::istream_view<int>>);
|
|
|
|
#ifndef TEST_HAS_NO_WIDE_CHARACTERS
|
|
static_assert(HasBegin<std::ranges::wistream_view<int>>);
|
|
static_assert(!HasBegin<const std::ranges::wistream_view<int>>);
|
|
#endif
|
|
|
|
template <class CharT>
|
|
void test() {
|
|
// begin should read the first element
|
|
{
|
|
auto iss = make_string_stream<CharT>("12 3");
|
|
std::ranges::basic_istream_view<int, CharT> isv{iss};
|
|
auto it = isv.begin();
|
|
assert(*it == 12);
|
|
}
|
|
|
|
// empty stream
|
|
{
|
|
auto iss = make_string_stream<CharT>("");
|
|
std::ranges::basic_istream_view<int, CharT> isv{iss};
|
|
auto it = isv.begin();
|
|
assert(it == isv.end());
|
|
}
|
|
}
|
|
|
|
int main(int, char**) {
|
|
test<char>();
|
|
#ifndef TEST_HAS_NO_WIDE_CHARACTERS
|
|
test<wchar_t>();
|
|
#endif
|
|
|
|
return 0;
|
|
}
|