On 26/06/19 19:13 -0400, Ed Smith-Rowland via libstdc++ wrote:
Here is the first of three patches for C++20 constexpr library.
?????? Implement C++20 p0202 - Add constexpr Modifiers to Functions in
<algorithm> and <utility> Headers.
???? ??Implement C++20 p1023 - constexpr comparison operators for std::array.
I believe I have answered peoples concerns with the last patch
attempts [https://gcc.gnu.org/ml/libstdc++/2019-03/msg00132.html].
The patch is large because of test cases but really just boils down to
adding constexpr for c++2a.
The patch passes testing for gnu++2a and pre-gnu++2a on x86_64-linux:
$ make check -k -j4
$ make check RUNTESTFLAGS=--target_board=unix/-std=gnu++2a -k -j4
OK for trunk?
One more comment. In <bits/stl_algobase.h> this:
+#if __cplusplus > 201703L \
+ && defined(_GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED)
+ if (__builtin_is_constant_evaluated())
can be simplified to just:
#ifdef __cpp_lib_is_constant_evaluated
if (std::is_constant_evaluated())
The feature test macro is exactly the check we want here.
