[PATCH] PR79114 use decayed type in std::throw_with_nested assertion

[Jonathan Wakely <jwakely at redhat dot com>]

I added a static assertion to enforce the CopyConstructible
requirement that the standard imposes for std::throw_with_nested.
Unfortunately the standard is defective, so we started rejecting
perfectly good code. This alters the check to what I think the
standard should say (and what I've proposed in a new issue against the
standard): we should check decay<T> not remove_reference<T>, because a
throw-expression decays arrays and functions to pointers.

	PR libstdc++/79114
	* libsupc++/nested_exception.h (throw_with_nested): Use decay instead
	of remove_reference.
	* testsuite/18_support/nested_exception/79114.cc: New test.

Tested powerpc64le-linux, committed to trunk.

Attachment: patch.txt
Description: Text document