[PATCH] PR libstdc++/89164 enforce constraints for uninitialized algos

[Jonathan Wakely <jwakely at redhat dot com>]

The memmove optimizations for std::uninitialized_copy/fill/_n will
compile even if the type is not copy constructible, because std::copy
doesn't require copy construction to work. But the uninitialized
algorithms do require it.

This adds explicit static assertions to ensure we don't allow ill-formed
initializations.

	PR libstdc++/89164
	* include/bits/stl_algobase.h (__copy_move): Give descriptive names
	to template parameters.
	* include/bits/stl_uninitialized.h (uninitialized_copy)
	(uninitialized_fill, uninitialized_fill_n): Add static assertions to
	diagnose invalid uses.
	* testsuite/20_util/specialized_algorithms/uninitialized_copy/1.cc:
	Adjust expected error.
	* testsuite/20_util/specialized_algorithms/uninitialized_copy/89164.cc:
	New test.
	* testsuite/20_util/specialized_algorithms/uninitialized_copy_n/
	89164.cc: New test.
	* testsuite/20_util/specialized_algorithms/uninitialized_fill/89164.cc:
	New test.
	* testsuite/20_util/specialized_algorithms/uninitialized_fill_n/
	89164.cc: New test.
	* testsuite/23_containers/vector/cons/89164.cc: New test.
	* testsuite/23_containers/vector/cons/89164_c++17.cc: New test.

This is the patch sent in
https://gcc.gnu.org/ml/libstdc++/2019-02/msg00034.html but with the
dg-error directives in the tests fixed.

Tested x86_64-linux, committed to trunk.

Attachment: patch.txt
Description: Text document