#1006 Compiler GCC - Use correct option for C++20 depending on version

[Miguel Gimenez]

A post in the forum shows a mismatch in options related to C++20, see: http://forums.codeblocks.org/index.php/topic,24079.0.html

The compiler options related to C++20 in GCC are a bit flawed. Currently they only appear if you have GCC 9 or 10, and always as -std=c++20 or -std=gnu++20. This is correct for GCC 10, but not for 9.

If you look at GCC standards support you can see C++20 is (partially) supported since version 8, and the option is -std=c++2a or -std=gnu++2a for GCC 8 or 9, and -std=c++20 or -std=gnu++20 for GCC = 10.

See: https://gcc.gnu.org/projects/cxx-status.html

The attached patch corrects this dividing the current entry into two, one for GCC 8 or 9 and other for GCC 10.

[Teodor Petrov]

This one depends on [#1041]

[Morten MacFly]

I am taking this one... I think I did the C++20 changes so its also my duty to correct them... :-)

[Teodor Petrov]

We have the version check now in trunk, so we could take advantage of it here probably.

[Miguel Gimenez]

This modified patch uses the new verbs to activate c++2a or c++20 depending on GCC version. Please note (line 64 of the patch) that support for C++20 was introduced in GCC 8, not in GCC 9.

[Teodor Petrov]

@mortenmacfly Are you going to push this patch or should I take it over?

[Morten MacFly]

Will do...

[Morten MacFly]

Applied in SVN. Thank you!