libstdc++: Add default_sentinel support to stream iterators

Missing pieces of P0896R4 "The One Ranges Proposal" for C++20.

	* include/bits/stream_iterator.h (istream_iterator(default_sentinel_t)):
	Add constructor.
	(operator==(istream_iterator, default_sentinel_t)): Add operator.
	(ostream_iterator::difference_type): Define to ptrdiff_t for C++20.
	* include/bits/streambuf_iterator.h
	(istreambuf_iterator(default_sentinel_t)): Add constructor.
	(operator==(istreambuf_iterator, default_sentinel_t)): Add operator.
	* testsuite/24_iterators/istream_iterator/cons/sentinel.cc:
	New test.
	* testsuite/24_iterators/istream_iterator/sentinel.cc: New test.
	* testsuite/24_iterators/istreambuf_iterator/cons/sentinel.cc:
	New test.
	* testsuite/24_iterators/istreambuf_iterator/sentinel.cc: New test.
This commit is contained in:
Jonathan Wakely 2020-02-24 13:11:31 +00:00
parent e03069be12
commit 120e873484
6 changed files with 150 additions and 0 deletions

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@ -1,5 +1,19 @@
2020-02-24 Jonathan Wakely <jwakely@redhat.com>
* include/bits/stream_iterator.h (istream_iterator(default_sentinel_t)):
Add constructor.
(operator==(istream_iterator, default_sentinel_t)): Add operator.
(ostream_iterator::difference_type): Define to ptrdiff_t for C++20.
* include/bits/streambuf_iterator.h
(istreambuf_iterator(default_sentinel_t)): Add constructor.
(operator==(istreambuf_iterator, default_sentinel_t)): Add operator.
* testsuite/24_iterators/istream_iterator/cons/sentinel.cc:
New test.
* testsuite/24_iterators/istream_iterator/sentinel.cc: New test.
* testsuite/24_iterators/istreambuf_iterator/cons/sentinel.cc:
New test.
* testsuite/24_iterators/istreambuf_iterator/sentinel.cc: New test.
* include/std/ranges (__deep_const_range, __enable_view_impl): Remove.
(ranges::enable_view): Simplify (LWG 3326).
* include/bits/range_access.h (ranges::enable_view): Declare.

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@ -77,6 +77,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_M_ok(__obj._M_ok)
{ }
#if __cplusplus > 201703L
constexpr
istream_iterator(default_sentinel_t) noexcept
: istream_iterator() { }
#endif
#if __cplusplus >= 201103L
istream_iterator& operator=(const istream_iterator&) = default;
~istream_iterator() = default;
@ -145,6 +151,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
friend bool
operator!=(const istream_iterator& __x, const istream_iterator& __y)
{ return !__x._M_equal(__y); }
#if __cplusplus > 201703L
friend bool
operator==(const istream_iterator& __i, default_sentinel_t)
{ return !__i._M_stream; }
#endif
};
/**
@ -166,6 +178,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
public:
//@{
/// Public typedef
#if __cplusplus > 201703L
using difference_type = ptrdiff_t;
#endif
typedef _CharT char_type;
typedef _Traits traits_type;
typedef basic_ostream<_CharT, _Traits> ostream_type;

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@ -115,6 +115,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX_CONSTEXPR istreambuf_iterator() _GLIBCXX_USE_NOEXCEPT
: _M_sbuf(0), _M_c(traits_type::eof()) { }
#if __cplusplus > 201703L
constexpr istreambuf_iterator(default_sentinel_t) noexcept
: istreambuf_iterator() { }
#endif
#if __cplusplus >= 201103L
istreambuf_iterator(const istreambuf_iterator&) noexcept = default;
@ -209,6 +214,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
const int_type __eof = traits_type::eof();
return traits_type::eq_int_type(__c, __eof);
}
#if __cplusplus > 201703L
friend bool
operator==(const istreambuf_iterator& __i, default_sentinel_t __s)
{ return __i._M_at_eof(); }
#endif
};
template<typename _CharT, typename _Traits>

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@ -0,0 +1,27 @@
// { dg-options "-std=gnu++2a" }
// { dg-do compile { target c++2a } }
// Copyright (C) 2020 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING3. If not see
// <http://www.gnu.org/licenses/>.
#include <iterator>
// C++20 doesn't require this to be non-throwing.
static_assert( std::is_nothrow_constructible_v<std::istream_iterator<int>,
std::default_sentinel_t> );
constexpr std::istream_iterator<int> i = std::default_sentinel;

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@ -0,0 +1,57 @@
// { dg-options "-std=gnu++2a" }
// { dg-do run { target c++2a } }
// Copyright (C) 2020 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING3. If not see
// <http://www.gnu.org/licenses/>.
#include <iterator>
#include <sstream>
#include <testsuite_hooks.h>
void
test01()
{
static_assert( std::sentinel_for<std::default_sentinel_t,
std::istream_iterator<std::string>> );
static_assert( std::sentinel_for<std::default_sentinel_t,
std::istream_iterator<int>> );
std::istream_iterator<int> i = std::default_sentinel;
VERIFY( i == std::default_sentinel );
VERIFY( std::default_sentinel == i );
}
void
test02()
{
std::istringstream in("1 2 3");
std::istream_iterator<int> iter(in);
VERIFY( iter != std::default_sentinel );
VERIFY( std::default_sentinel != iter );
*iter++;
*iter++;
*iter++;
VERIFY( iter == std::default_sentinel );
VERIFY( std::default_sentinel == iter );
}
int main()
{
test01();
test02();
}

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@ -0,0 +1,26 @@
// { dg-options "-std=gnu++2a" }
// { dg-do compile { target c++2a } }
// Copyright (C) 2020 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING3. If not see
// <http://www.gnu.org/licenses/>.
#include <iterator>
static_assert( std::is_nothrow_constructible_v<std::istreambuf_iterator<char>,
std::default_sentinel_t> );
constexpr std::istreambuf_iterator<char> i = std::default_sentinel;