[PATCH] PR libstdc++/92059 fix several bugs in tr2::dynamic_bitset

[Jonathan Wakely <jwakely at redhat dot com>]

	PR libstdc++/92059
	* include/tr2/dynamic_bitset (__dynamic_bitset_base): Define all
	special member functions as defaulted. Add noexcept to most members.
	(__dynamic_bitset_base(size_t, unsigned long long, const _Alloc&)):
	Mask off unwanted bits in the __val parameter. Avoid undefined left
	shifts.
	(__dynamic_bitset_base::_M_assign): Remove.
	(__dynamic_bitset_base::_M_do_reset): Use std::fill.
	(__dynamic_bitset_base::_M_are_all_aux): Avoid integer promotion when
	block_type has lower rank than int.
	(dynamic_bitset): Add noexcept to most members. Use injected-class-name
	in return types and parameter types.
	(dynamic_bitset::_M_Nb): Add default member initializer.
	(dynamic_bitset(), dynamic_bitset(const dynamic_bitset&)): Define as
	defaulted.
	(dynamic_bitset(dynamic_bitset&&)): Clear source object after move.
	(dynamic_bitset::operator=(const dynamic_bitset&)): Define as
	defaulted.
	(dynamic_bitset::operator=(dynamic_bitset&&)): Add noexcept-specifier.
	Define without using swap, to propagate allocator correctly.
	(dynamic_bitset(const char*, const _Alloc&)): Use strlen.
	(dynamic_bitset::_M_do_sanitize, dynamic_bitset::_M_do_fill): Use
	casts to avoid unwanted integer promotions.
	(dynamic_bitset::_M_copy_from_ptr): Rearrange template parameters and
	add default template arguments and default argument to simplify usage.
	(dynamic_bitset::_M_copy_from_string): Adjust call to _M_copy_from_ptr.
	(operator==(const dynamic_bitset&, const dynamic_bitset&))
	(operator<(const dynamic_bitset&, const dynamic_bitset&)): Use _M_Nb.
	* include/tr2/dynamic_bitset.tcc (dynamic_bitset::_M_copy_from_ptr):
	Adjust template parameters to match declaration.
	* testsuite/tr2/dynamic_bitset/cmp.cc: New test.
	* testsuite/tr2/dynamic_bitset/cons.cc: New test.
	* testsuite/tr2/dynamic_bitset/copy.cc: New test.
	* testsuite/tr2/dynamic_bitset/move.cc: New test.
	* testsuite/tr2/dynamic_bitset/pr92059.cc: New test.

Tested x86_64-linux. Committed to trunk.

This seems worth backporting too, as the type is now no longer totally
broken (e.g. it is now copy constructible, and the move constructor no
longer breaks the class invariant).

Attachment: patch.txt
Description: Text document