On 06/05/18 16:06 +0200, François Dumont wrote:
Here is the rework of this patch.
On 02/05/2018 13:49, Jonathan Wakely wrote:
There's no changelog entry with the patch, so to recap, the changes
are:
- noexcept specifications are automatically deduced instead of being
stated explicitly.
I simplified this part, it is not deduced anymore except for Debug
mode relying on Normal mode qualifications.
- The allocator-extended move constructors get correct exception
specifications in Debug Mode (consistent with normal mode). This
should be done anyway, independent of any other changes.
I kept this untouch.
- We avoid a `if (__x._M_root() != nullptr)` branch in the case where
the allocator-extended move constructor is used with an always-equal
allocator, right?
Kept too.
Compilation time for containers is already **much** slower since the
allocator-extended constructors were added for GCC 5.x, despite very
few people ever using those constructors. This patch seems to require
even more work from the compiler to parse constructors nobody uses.
I restore direct qualifications.
diff --git a/libstdc++-v3/include/bits/stl_map.h
b/libstdc++-v3/include/bits/stl_map.h
index a4a026e..2b8fd27 100644
--- a/libstdc++-v3/include/bits/stl_map.h
+++ b/libstdc++-v3/include/bits/stl_map.h
@@ -240,8 +240,8 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
/// Allocator-extended move constructor.
map(map&& __m, const allocator_type& __a)
- noexcept(is_nothrow_copy_constructible<_Compare>::value
- && _Alloc_traits::_S_always_equal())
+ noexcept( noexcept(
+ _Rep_type(std::move(__m._M_t), declval<_Pair_alloc_type>())) )
All these calls to declval need to be qualified to avoid ADL.
It seems strange to have a mix of real values and declval expressions,
rather than:
_Rep_type(std::declval<_Rep_type>(),
std::declval<_Pair_alloc_type>())) )
I add std:: qualitification and generalized usage.
- _Rb_tree(_Rb_tree&& __x, _Node_allocator&& __a);
+ private:
+ _Rb_tree(_Rb_tree&& __x, _Node_allocator&& __a, true_type)
+ noexcept(is_nothrow_move_constructible<_Rb_tree_impl<_Compare>>::value)
This is wrong.
As stated previously I removed this but based on this remark I also
change the _Rb_tree_impl() qualification so that it doesn't depend
anymore on allocator default constructor qualification.
I've added a test for that too.
This can use std::is_nothrow_constructible
Indeed.
+ "noexcept move constructor with allocator" );
+
+struct ExceptLess
Please name this "ThrowingLess" instead of "ExceptLess", I think
that's more descriptive.
I prefered "not_noexcept" prefix cause those operators are not
throwing anything neither.
Tested under Linux x86_64, ok to commit ?
* include/bits/stl_tree.h
(_Rb_tree_impl()):
Remove is_nothrow_default_constructible<_Node_allocator> from noexcept
qualification.
(_Rb_tree_impl(_Rb_tree_impl&&, _Node_allocator&&)): New.
(_Rb_tree(_Rb_tree&&, _Node_allocator&&, std::true_type)): New,
use latter.
(_Rb_tree(_Rb_tree&&, _Node_allocator&&, std::false_type)): New.
(_Rb_tree(_Rb_tree&&, _Node_allocator&&)): Adapt, use latters.
* include/debug/map.h
(map(map&&, const_allocator_type&)): Add noexcept qualitication.
* include/debug/multimap.h
(multimap(multimap&&, const_allocator_type&)): Add noexcept
qualification.
* include/debug/set.h
(set(set&&, const_allocator_type&)): Add noexcept qualitication.
* include/debug/multiset.h
(multiset(multiset&&, const_allocator_type&)): Add noexcept
qualification.
* testsuite/23_containers/map/cons/noexcept_default_construct.cc:
Add checks.
* testsuite/23_containers/map/cons/noexcept_move_construct.cc:
Add checks.
* testsuite/23_containers/multimap/cons/noexcept_default_construct.cc:
Add checks.
* testsuite/23_containers/multimap/cons/noexcept_move_construct.cc:
Add checks.
* testsuite/23_containers/multiset/cons/noexcept_default_construct.cc:
Add checks.
* testsuite/23_containers/multiset/cons/noexcept_move_construct.cc:
Add checks.
* testsuite/23_containers/set/cons/noexcept_default_construct.cc:
Add checks.
* testsuite/23_containers/set/cons/noexcept_move_construct.cc:
Add checks.
François
diff --git a/libstdc++-v3/include/bits/stl_tree.h
b/libstdc++-v3/include/bits/stl_tree.h
index d0a8448..9e59259 100644
--- a/libstdc++-v3/include/bits/stl_tree.h
+++ b/libstdc++-v3/include/bits/stl_tree.h
@@ -698,8 +698,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_Rb_tree_impl()
_GLIBCXX_NOEXCEPT_IF(
- is_nothrow_default_constructible<_Node_allocator>::value
- && is_nothrow_default_constructible<_Base_key_compare>::value )
+ // is_nothrow_default_constructible<_Node_allocator>::value &&
+ is_nothrow_default_constructible<_Base_key_compare>::value )
: _Node_allocator()
{ }
This part wasn't in the previous patch and seems wrong:
https://cplusplus.github.io/LWG/issue2455
