git
/
gcc
mirror of git://gcc.gnu.org/git/gcc.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Add [[nodiscard]] attribute to C++17 components 

* include/bits/fs_path.h (path::empty): Add nodiscard attribute.
	* include/bits/range_access.h (empty): Likewise.
	* include/std/string_view (basic_string_view::empty): Likewise.
	* testsuite/21_strings/basic_string_view/capacity/empty_neg.cc: New
	test.
	* testsuite/24_iterators/range_access_cpp17_neg.cc: New test.
	* testsuite/27_io/filesystem/path/query/empty_neg.cc: New test.

From-SVN: r255124
This commit is contained in:
Jonathan Wakely 2017-11-23 22:11:21 +00:00 committed by Jonathan Wakely
parent 4b9840f230
commit d69f1ec7d1
8 changed files with 114 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
libstdc++-v3/ChangeLog
View File

@ -1,5 +1,13 @@
2017-11-23 Jonathan Wakely <jwakely@redhat.com>
* include/bits/fs_path.h (path::empty): Add nodiscard attribute.
* include/bits/range_access.h (empty): Likewise.
* include/std/string_view (basic_string_view::empty): Likewise.
* testsuite/21_strings/basic_string_view/capacity/empty_neg.cc: New
test.
* testsuite/24_iterators/range_access_cpp17_neg.cc: New test.
* testsuite/27_io/filesystem/path/query/empty_neg.cc: New test.
PR libstdc++/83134
* include/std/type_traits (__not_): Explicitly convert to bool.
* testsuite/20_util/declval/requirements/1_neg.cc: Adjust dg-error.

2
libstdc++-v3/include/bits/fs_path.h
View File

@ -370,7 +370,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
// query
bool empty() const noexcept { return _M_pathname.empty(); }
[[nodiscard]] bool empty() const noexcept { return _M_pathname.empty(); }
bool has_root_name() const;
bool has_root_directory() const;
bool has_root_path() const;

2
libstdc++-v3/include/bits/node_handle.h
View File

@ -62,7 +62,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
explicit operator bool() const noexcept { return _M_ptr != nullptr; }
bool empty() const noexcept { return _M_ptr == nullptr; }
[[nodiscard]] bool empty() const noexcept { return _M_ptr == nullptr; }
protected:
constexpr _Node_handle_common() noexcept : _M_ptr(), _M_alloc() {}

6
libstdc++-v3/include/bits/range_access.h
View File

@ -257,7 +257,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
* @param __cont Container.
*/
template <typename _Container>
constexpr auto
[[nodiscard]] constexpr auto
empty(const _Container& __cont) noexcept(noexcept(__cont.empty()))
-> decltype(__cont.empty())
{ return __cont.empty(); }
@ -267,7 +267,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
* @param __array Container.
*/
template <typename _Tp, size_t _Nm>
constexpr bool
[[nodiscard]] constexpr bool
empty(const _Tp (&/*__array*/)[_Nm]) noexcept
{ return false; }
@ -276,7 +276,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
* @param __il Initializer list.
*/
template <typename _Tp>
constexpr bool
[[nodiscard]] constexpr bool
empty(initializer_list<_Tp> __il) noexcept
{ return __il.size() == 0;}

2
libstdc++-v3/include/std/string_view
View File

@ -160,7 +160,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
/ sizeof(value_type) / 4;
}
constexpr bool
[[nodiscard]] constexpr bool
empty() const noexcept
{ return this->_M_len == 0; }

28
libstdc++-v3/testsuite/21_strings/basic_string_view/capacity/empty_neg.cc Normal file
View File

@ -0,0 +1,28 @@
// Copyright (C) 2017 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/>.
// { dg-options "-std=gnu++17" }
// { dg-do compile { target c++17 } }
#include <string_view>
void
test01()
{
std::string_view s;
s.empty(); // { dg-warning "ignoring return value" }
}

44
libstdc++-v3/testsuite/24_iterators/range_access_cpp17_neg.cc Normal file
View File

@ -0,0 +1,44 @@
// Copyright (C) 2017 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/>.
// { dg-options "-std=gnu++17" }
// { dg-do compile { target c++17 } }
#include <iterator>
#include <initializer_list>
void
test01()
{
struct A { bool empty() const { return true; } };
A a;
std::empty(a); // { dg-warning "ignoring return value" }
}
void
test02()
{
int a[2];
std::empty(a); // { dg-warning "ignoring return value" }
}
void
test03()
{
std::initializer_list<int> a{};
std::empty(a); // { dg-warning "ignoring return value" }
}

28
libstdc++-v3/testsuite/27_io/filesystem/path/query/empty_neg.cc Normal file
View File

@ -0,0 +1,28 @@
// Copyright (C) 2017 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/>.
// { dg-options "-std=gnu++17" }
// { dg-do compile { target c++17 } }
#include <filesystem>
void
test01()
{
std::filesystem::path p;
p.empty(); // { dg-warning "ignoring return value" }
}