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
58 lines
1.7 KiB
C++
58 lines
1.7 KiB
C++
//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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// UNSUPPORTED: no-localization
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// UNSUPPORTED: c++03, c++11, c++14, c++17
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// constexpr explicit basic_istream_view(basic_istream<CharT, Traits>& stream);
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#include <cassert>
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#include <ranges>
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#include <sstream>
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#include "test_macros.h"
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#include "utils.h"
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// test that the constructor is explicit
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static_assert(std::constructible_from<std::ranges::istream_view<int>, std::istream&>);
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static_assert(!std::convertible_to<std::istream&, std::ranges::istream_view<int>>);
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#ifndef TEST_HAS_NO_WIDE_CHARACTERS
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static_assert(std::constructible_from<std::ranges::wistream_view<int>, std::wistream&>);
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static_assert(!std::convertible_to<std::wistream&, std::ranges::wistream_view<int>>);
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#endif
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template <class CharT>
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void test() {
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// test constructor init the stream pointer to the passed one
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{
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auto iss = make_string_stream<CharT>("123");
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std::ranges::basic_istream_view<int, CharT> isv{iss};
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auto it = isv.begin();
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assert(*it == 123);
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}
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// LWG 3568. basic_istream_view needs to initialize value_
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{
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auto iss = make_string_stream<CharT>("123");
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std::ranges::basic_istream_view<int, CharT> isv{iss};
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using Iter = std::ranges::iterator_t<decltype(isv)>;
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Iter iter{isv};
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assert(*iter == 0);
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}
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}
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int main(int, char**) {
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test<char>();
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#ifndef TEST_HAS_NO_WIDE_CHARACTERS
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test<wchar_t>();
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#endif
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return 0;
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}
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