From: Jonathan Wakely Date: Fri, 17 Aug 2018 17:52:49 +0000 (+0100) Subject: PR libstdc++/86963 Implement LWG 2729 constraints on tuple assignment X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=478490f681da504e75723828d9f1b3b09928b5e5;p=gcc.git PR libstdc++/86963 Implement LWG 2729 constraints on tuple assignment PR libstdc++/86963 * include/std/tuple (__tuple_base): New class template with deleted copy assignment operator. (tuple, tuple<_T1, _T2>): Derive from __tuple_base so that implicit copy/move assignment operator will be deleted/suppressed. (tuple::__assignable, tuple<_T1, _T2>::__assignable): New helper functions for SFINAE constraints on assignment operators. (tuple::__nothrow_assignable, tuple<_T1, _T2>::__nothrow_assignable): New helper functions for exception specifications. (tuple::operator=(const tuple&), tuple::operator=(tuple&&)) (tuple<_T1, _T2>::operator=(const tuple&)) (tuple<_T1, _T2>::operator=(tuple&&)): Change parameter types to __nonesuch_no_braces when the operator should be defined implicitly. Use __nothrow_assignable for exception specifications. (tuple::operator=(const tuple<_UElements...>&)) (tuple::operator=(tuple<_UElements...>&&)) (tuple<_T1, _T2>::operator=(const tuple<_U1, _U2>&)) (tuple<_T1, _T2>::operator=(tuple<_U1, _U2>&&)) (tuple<_T1, _T2>::operator=(const pair<_U1, _U2>&)) (tuple<_T1, _T2>::operator=(pair<_U1, _U2>&&)): Constrain using __assignable and use __nothrow_assignable for exception specifications. * python/libstdcxx/v6/printers.py (is_specialization_of): Accept gdb.Type as first argument, instead of a string. (StdTuplePrinter._iterator._is_nonempty_tuple): New method to check tuple for expected structure. (StdTuplePrinter._iterator.__init__): Use _is_nonempty_tuple. * testsuite/20_util/tuple/dr2729.cc: New test. * testsuite/20_util/tuple/element_access/get_neg.cc: Change dg-error to dg-prune-output. From-SVN: r263625 --- diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index 9477a33fb7f..95d4d06bf35 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,3 +1,36 @@ +2018-08-17 Jonathan Wakely + + PR libstdc++/86963 + * include/std/tuple (__tuple_base): New class template with deleted + copy assignment operator. + (tuple, tuple<_T1, _T2>): Derive from __tuple_base so that + implicit copy/move assignment operator will be deleted/suppressed. + (tuple::__assignable, tuple<_T1, _T2>::__assignable): New helper + functions for SFINAE constraints on assignment operators. + (tuple::__nothrow_assignable, tuple<_T1, _T2>::__nothrow_assignable): + New helper functions for exception specifications. + (tuple::operator=(const tuple&), tuple::operator=(tuple&&)) + (tuple<_T1, _T2>::operator=(const tuple&)) + (tuple<_T1, _T2>::operator=(tuple&&)): Change parameter types to + __nonesuch_no_braces when the operator should be defined implicitly. + Use __nothrow_assignable for exception specifications. + (tuple::operator=(const tuple<_UElements...>&)) + (tuple::operator=(tuple<_UElements...>&&)) + (tuple<_T1, _T2>::operator=(const tuple<_U1, _U2>&)) + (tuple<_T1, _T2>::operator=(tuple<_U1, _U2>&&)) + (tuple<_T1, _T2>::operator=(const pair<_U1, _U2>&)) + (tuple<_T1, _T2>::operator=(pair<_U1, _U2>&&)): Constrain using + __assignable and use __nothrow_assignable for exception + specifications. + * python/libstdcxx/v6/printers.py (is_specialization_of): Accept + gdb.Type as first argument, instead of a string. + (StdTuplePrinter._iterator._is_nonempty_tuple): New method to check + tuple for expected structure. + (StdTuplePrinter._iterator.__init__): Use _is_nonempty_tuple. + * testsuite/20_util/tuple/dr2729.cc: New test. + * testsuite/20_util/tuple/element_access/get_neg.cc: Change dg-error + to dg-prune-output. + 2018-08-16 Jonathan Wakely * include/tr1/legendre_function.tcc (__sph_legendre): Avoid warning diff --git a/libstdc++-v3/include/std/tuple b/libstdc++-v3/include/std/tuple index dd7daf7f1cf..955b853066f 100644 --- a/libstdc++-v3/include/std/tuple +++ b/libstdc++-v3/include/std/tuple @@ -551,9 +551,23 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION } }; + // The tag parameter ensures that in nested tuples each __tuple_base + // is a different type and can use the empty base-class optimisation. + template + class __tuple_base + { + template friend struct tuple; + __tuple_base() = default; + ~__tuple_base() = default; + __tuple_base(const __tuple_base&) = default; + __tuple_base& operator=(const __tuple_base&) = delete; + }; + /// Primary class template, tuple template - class tuple : public _Tuple_impl<0, _Elements...> + class tuple + : public _Tuple_impl<0, _Elements...>, + private __tuple_base> { typedef _Tuple_impl<0, _Elements...> _Inherited; @@ -573,6 +587,19 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION } }; + template + static constexpr + __enable_if_t + __assignable() + { return __and_...>::value; } + + template + static constexpr bool __nothrow_assignable() + { + return + __and_...>::value; + } + public: template:: @@ -832,36 +859,39 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { } tuple& - operator=(const tuple& __in) + operator=(typename conditional<__assignable(), + const tuple&, + const __nonesuch_no_braces&>::type __in) + noexcept(__nothrow_assignable()) { static_cast<_Inherited&>(*this) = __in; return *this; } tuple& - operator=(tuple&& __in) - noexcept(is_nothrow_move_assignable<_Inherited>::value) + operator=(typename conditional<__assignable<_Elements...>(), + tuple&&, + __nonesuch_no_braces&&>::type __in) + noexcept(__nothrow_assignable<_Elements...>()) { static_cast<_Inherited&>(*this) = std::move(__in); return *this; } template - typename - enable_if::type - operator=(const tuple<_UElements...>& __in) - { + __enable_if_t<__assignable(), tuple&> + operator=(const tuple<_UElements...>& __in) + noexcept(__nothrow_assignable()) + { static_cast<_Inherited&>(*this) = __in; return *this; } template - typename - enable_if::type - operator=(tuple<_UElements...>&& __in) - { + __enable_if_t<__assignable<_UElements...>(), tuple&> + operator=(tuple<_UElements...>&& __in) + noexcept(__nothrow_assignable<_UElements...>()) + { static_cast<_Inherited&>(*this) = std::move(__in); return *this; } @@ -904,10 +934,26 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION /// Partial specialization, 2-element tuple. /// Includes construction and assignment from a pair. template - class tuple<_T1, _T2> : public _Tuple_impl<0, _T1, _T2> + class tuple<_T1, _T2> + : public _Tuple_impl<0, _T1, _T2>, + private __tuple_base> { typedef _Tuple_impl<0, _T1, _T2> _Inherited; + template + static constexpr bool __assignable() + { + return __and_, + is_assignable<_T2&, _U2>>::value; + } + + template + static constexpr bool __nothrow_assignable() + { + return __and_, + is_nothrow_assignable<_T2&, _U2>>::value; + } + public: template , __is_implicitly_default_constructible<_U2>> ::value, bool>::type = true> - - constexpr tuple() - : _Inherited() { } + constexpr tuple() + : _Inherited() { } template , __is_implicitly_default_constructible<_U2>>>> ::value, bool>::type = false> - - explicit constexpr tuple() - : _Inherited() { } + explicit constexpr tuple() + : _Inherited() { } // Shortcut for the cases where constructors taking _T1, _T2 // need to be constrained. @@ -1206,49 +1250,58 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION std::forward<_U2>(__in.second)) { } tuple& - operator=(const tuple& __in) + operator=(typename conditional<__assignable(), + const tuple&, + const __nonesuch_no_braces&>::type __in) + noexcept(__nothrow_assignable()) { static_cast<_Inherited&>(*this) = __in; return *this; } tuple& - operator=(tuple&& __in) - noexcept(is_nothrow_move_assignable<_Inherited>::value) + operator=(typename conditional<__assignable<_T1, _T2>(), + tuple&&, + __nonesuch_no_braces&&>::type __in) + noexcept(__nothrow_assignable<_T1, _T2>()) { static_cast<_Inherited&>(*this) = std::move(__in); return *this; } template - tuple& - operator=(const tuple<_U1, _U2>& __in) - { + __enable_if_t<__assignable(), tuple&> + operator=(const tuple<_U1, _U2>& __in) + noexcept(__nothrow_assignable()) + { static_cast<_Inherited&>(*this) = __in; return *this; } template - tuple& - operator=(tuple<_U1, _U2>&& __in) - { + __enable_if_t<__assignable<_U1, _U2>(), tuple&> + operator=(tuple<_U1, _U2>&& __in) + noexcept(__nothrow_assignable<_U1, _U2>()) + { static_cast<_Inherited&>(*this) = std::move(__in); return *this; } template - tuple& - operator=(const pair<_U1, _U2>& __in) - { + __enable_if_t<__assignable(), tuple&> + operator=(const pair<_U1, _U2>& __in) + noexcept(__nothrow_assignable()) + { this->_M_head(*this) = __in.first; this->_M_tail(*this)._M_head(*this) = __in.second; return *this; } template - tuple& - operator=(pair<_U1, _U2>&& __in) - { + __enable_if_t<__assignable<_U1, _U2>(), tuple&> + operator=(pair<_U1, _U2>&& __in) + noexcept(__nothrow_assignable<_U1, _U2>()) + { this->_M_head(*this) = std::forward<_U1>(__in.first); this->_M_tail(*this)._M_head(*this) = std::forward<_U2>(__in.second); return *this; diff --git a/libstdc++-v3/python/libstdcxx/v6/printers.py b/libstdc++-v3/python/libstdcxx/v6/printers.py index 43d459ec8ec..afe1b325d87 100644 --- a/libstdc++-v3/python/libstdcxx/v6/printers.py +++ b/libstdc++-v3/python/libstdcxx/v6/printers.py @@ -101,12 +101,14 @@ def find_type(orig, name): _versioned_namespace = '__8::' -def is_specialization_of(type, template_name): +def is_specialization_of(x, template_name): "Test if a type is a given template instantiation." global _versioned_namespace + if type(x) is gdb.Type: + x = x.tag if _versioned_namespace: - return re.match('^std::(%s)?%s<.*>$' % (_versioned_namespace, template_name), type) is not None - return re.match('^std::%s<.*>$' % template_name, type) is not None + return re.match('^std::(%s)?%s<.*>$' % (_versioned_namespace, template_name), x) is not None + return re.match('^std::%s<.*>$' % template_name, x) is not None def strip_versioned_namespace(typename): global _versioned_namespace @@ -413,17 +415,26 @@ class StdTuplePrinter: "Print a std::tuple" class _iterator(Iterator): + @staticmethod + def _is_nonempty_tuple (nodes): + if len (nodes) == 2: + if is_specialization_of (nodes[1].type, '__tuple_base'): + return True + elif len (nodes) == 1: + return True + elif len (nodes) == 0: + return False + raise ValueError("Top of tuple tree does not consist of a single node.") + def __init__ (self, head): self.head = head # Set the base class as the initial head of the # tuple. nodes = self.head.type.fields () - if len (nodes) == 1: + if self._is_nonempty_tuple (nodes): # Set the actual head to the first pair. self.head = self.head.cast (nodes[0].type) - elif len (nodes) != 0: - raise ValueError("Top of tuple tree does not consist of a single node.") self.count = 0 def __iter__ (self): diff --git a/libstdc++-v3/testsuite/20_util/tuple/dr2729.cc b/libstdc++-v3/testsuite/20_util/tuple/dr2729.cc new file mode 100644 index 00000000000..c3863557994 --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/tuple/dr2729.cc @@ -0,0 +1,179 @@ +// Copyright (C) 2018 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 +// . + +// { dg-do compile { target c++11 } } + +#include +#include + +using std::tuple; +using std::pair; +using __gnu_test::assign::AnyAssign; +using __gnu_test::assign::DelAnyAssign; +using __gnu_test::assign::DelCopyAssign; +using __gnu_test::CopyConsOnlyType; + +// Copy assignment: +template +constexpr bool copy() { return std::is_copy_assignable::value; } + +// Move assigmment: +template +constexpr bool move() { return std::is_move_assignable::value; } + +static_assert( copy>(), ""); +static_assert( move>(), ""); + +static_assert( copy>(), ""); +static_assert( copy>(), ""); +static_assert( copy>(), ""); +static_assert( copy>(), ""); +static_assert( copy>(), ""); +static_assert( copy>(), ""); +static_assert( copy>(), ""); +static_assert( copy>(), ""); +static_assert( copy>(), ""); +static_assert( copy>(), ""); +static_assert( copy>(), ""); + +static_assert( move>(), ""); +static_assert( move>(), ""); +static_assert( move>(), ""); +static_assert( move>(), ""); +static_assert( move>(), ""); +static_assert( move>(), ""); +static_assert( move>(), ""); +static_assert( move>(), ""); +static_assert( move>(), ""); +static_assert( move>(), ""); +static_assert( move>(), ""); + +static_assert( ! copy>(), ""); +static_assert( ! copy>(), ""); +static_assert( ! copy>(), ""); +static_assert( ! copy>(), ""); +static_assert( ! copy>(), ""); +static_assert( ! copy>(), ""); + +static_assert( move>(), ""); +static_assert( move>(), ""); +static_assert( move>(), ""); +static_assert( move>(), ""); +static_assert( move>(), ""); +static_assert( move>(), ""); + +static_assert( ! move>(), ""); +static_assert( ! move>(), ""); +static_assert( ! move>(), ""); +static_assert( ! move>(), ""); +static_assert( ! move>(), ""); +static_assert( ! move>(), ""); + +// Assignment from different types of tuple (and pair): +template +constexpr bool assign() { return std::is_assignable::value; } + +// 0-tuples +static_assert( ! assign, tuple>(), "" ); +static_assert( ! assign, const tuple&>(), "" ); + +// 1-tuples +static_assert( ! assign, tuple<>>(), "" ); +static_assert( ! assign, const tuple<>&>(), "" ); +static_assert( ! assign, tuple<>>(), "" ); +static_assert( ! assign, tuple>(), "" ); +static_assert( ! assign, pair>(), "" ); + +static_assert( ! assign, tuple>(), "" ); +static_assert( ! assign, const tuple&>(), "" ); + +static_assert( assign, tuple>(), "" ); +static_assert( assign, tuple&>(), "" ); +static_assert( assign, const tuple>(), "" ); +static_assert( assign, const tuple&>(), "" ); + +// 2-tuples +static_assert( assign, tuple>(), "" ); +static_assert( assign, tuple&>(), "" ); +static_assert( assign, const tuple>(), "" ); +static_assert( assign, const tuple&>(), "" ); + +static_assert( assign, pair>(), "" ); +static_assert( assign, const pair&>(), "" ); +static_assert( assign, pair>(), "" ); +static_assert( assign, const pair&&>(), "" ); + +static_assert( assign, + tuple>(), "" ); +static_assert( ! assign, + tuple&>(), "" ); +static_assert( ! assign, + const tuple&>(), "" ); +static_assert( ! assign, + const tuple&&>(), "" ); + +static_assert( assign, + tuple>(), "" ); +static_assert( ! assign, + tuple&>(), "" ); +static_assert( ! assign, + const tuple&>(), "" ); +static_assert( ! assign, + const tuple&&>(), "" ); + +static_assert( ! assign, + tuple>(), "" ); +static_assert( ! assign, + const tuple&>(), "" ); + +static_assert( assign, + pair>(), "" ); +static_assert( ! assign, + pair&>(), "" ); +static_assert( ! assign, + const pair&>(), "" ); +static_assert( ! assign, + const pair&&>(), "" ); + +static_assert( assign, + pair>(), "" ); +static_assert( ! assign, + pair&>(), "" ); +static_assert( ! assign, + const pair&>(), "" ); +static_assert( ! assign, + const pair&&>(), "" ); + +static_assert( ! assign, + pair>(), "" ); +static_assert( ! assign, + const pair&>(), "" ); + +// 3-tuples +static_assert( assign, + tuple>(), "" ); +static_assert( ! assign, + tuple&>(), "" ); +static_assert( ! assign, + const tuple&>(), "" ); +static_assert( ! assign, + const tuple&&>(), "" ); + +static_assert( ! assign, + tuple>(), "" ); +static_assert( ! assign, + const tuple&>(), "" ); diff --git a/libstdc++-v3/testsuite/20_util/tuple/element_access/get_neg.cc b/libstdc++-v3/testsuite/20_util/tuple/element_access/get_neg.cc index e76f53aff6e..d55028268eb 100644 --- a/libstdc++-v3/testsuite/20_util/tuple/element_access/get_neg.cc +++ b/libstdc++-v3/testsuite/20_util/tuple/element_access/get_neg.cc @@ -17,7 +17,7 @@ // { dg-options "-fno-show-column" } // { dg-do compile { target c++14 } } -// { dg-error "in range" "" { target *-*-* } 1297 } +// { dg-prune-output "tuple index is in range" } #include