tree d99eda48492403db22b27b3b4d12fa67a8127b34
parent dc78d691c5e5f72cd05113c4734985aa4e70cc47
author Nathan Myers <ncm@cantrip.org> 1751577340 -0400
committer Nathan Myers <ncm@cantrip.org> 1758317491 -0400

libstdc++: Add NTTP bind_front, -back, not_fn (P2714) [PR119744]

Add non-type template parameter function-object/-pointer argument
versions of bind_front, bind_back, and not_fn.

This introduces a new internal type _Bind_fn_t to carry the
template-argument function object when no arguments are bound,
used in both bind_front and bind_back. Otherwise they return
a lambda object that has captured the arguments.

There is no need to change libstdc++-v3/src/c++23/std.cc.in
because existing exports: "using std::bind_front;" etc. export
the new overloads.

libstdc++-v3/ChangeLog:
	PR libstdc++/119744
	* include/bits/version.def: Redefine __cpp_lib_bind_front etc.
	* include/bits/version.h: Ditto.
	* include/std/functional: Add new bind_front etc. overloads
	* testsuite/20_util/function_objects/bind_back/1.cc:
	Check plumbing better
	* testsuite/20_util/function_objects/bind_back/nttp.cc: New test.
	* testsuite/20_util/function_objects/bind_back/nttp_neg.cc: New test.
	* testsuite/20_util/function_objects/bind_front/1.cc:
	Check plumbing better
	* testsuite/20_util/function_objects/bind_front/nttp.cc: New test.
	* testsuite/20_util/function_objects/bind_front/nttp_neg.cc: New test.
	* testsuite/20_util/function_objects/not_fn/nttp.cc: New test.
	* testsuite/20_util/function_objects/not_fn/nttp_neg.cc: New test.
	* testsuite/20_util/headers/functional/synopsis.cc: New decls.