| 1 | //===----------------------------------------------------------------------===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | |
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| 9 | // <istream> |
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| 10 | |
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| 11 | // template <class Stream, class T> |
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| 12 | // Stream&& operator>>(Stream&& is, T&& x); |
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| 13 | |
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| 14 | #include <istream> |
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| 15 | #include <sstream> |
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| 16 | #include <cassert> |
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| 17 | |
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| 18 | #include "test_macros.h" |
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| 19 | |
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| 20 | template <class CharT> |
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| 21 | struct testbuf |
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| 22 | : public std::basic_streambuf<CharT> |
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| 23 | { |
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| 24 | typedef std::basic_string<CharT> string_type; |
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| 25 | typedef std::basic_streambuf<CharT> base; |
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| 26 | private: |
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| 27 | string_type str_; |
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| 28 | public: |
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| 29 | |
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| 30 | testbuf() {} |
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| 31 | testbuf(const string_type& str) |
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| 32 | : str_(str) |
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| 33 | { |
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| 34 | base::setg(const_cast<CharT*>(str_.data()), |
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| 35 | const_cast<CharT*>(str_.data()), |
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| 36 | const_cast<CharT*>(str_.data()) + str_.size()); |
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| 37 | } |
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| 38 | |
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| 39 | CharT* eback() const {return base::eback();} |
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| 40 | CharT* gptr() const {return base::gptr();} |
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| 41 | CharT* egptr() const {return base::egptr();} |
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| 42 | }; |
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| 43 | |
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| 44 | struct Int { |
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| 45 | int value; |
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| 46 | template <class CharT> |
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| 47 | friend void operator>>(std::basic_istream<CharT>& is, Int& self) { |
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| 48 | is >> self.value; |
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| 49 | } |
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| 50 | }; |
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| 51 | |
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| 52 | struct A { }; |
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| 53 | bool called = false; |
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| 54 | void operator>>(std::istream&, A&&) { called = true; } |
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| 55 | |
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| 56 | int main(int, char**) |
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| 57 | { |
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| 58 | { |
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| 59 | testbuf<char> sb(" 123" ); |
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| 60 | Int i = {.value: 0}; |
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| 61 | std::istream is(&sb); |
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| 62 | std::istream&& result = (std::move(is) >> i); |
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| 63 | assert(&result == &is); |
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| 64 | assert(i.value == 123); |
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| 65 | } |
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| 66 | #ifndef TEST_HAS_NO_WIDE_CHARACTERS |
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| 67 | { |
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| 68 | testbuf<wchar_t> sb(L" 123" ); |
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| 69 | Int i = {.value: 0}; |
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| 70 | std::wistream is(&sb); |
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| 71 | std::wistream&& result = (std::move(is) >> i); |
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| 72 | assert(&result == &is); |
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| 73 | assert(i.value == 123); |
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| 74 | } |
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| 75 | #endif |
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| 76 | { |
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| 77 | // test perfect forwarding |
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| 78 | assert(called == false); |
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| 79 | std::istringstream ss; |
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| 80 | std::istringstream&& result = (std::move(ss) >> A()); |
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| 81 | assert(&result == &ss); |
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| 82 | assert(called); |
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| 83 | } |
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| 84 | |
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| 85 | return 0; |
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| 86 | } |
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| 87 | |
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