<div dir="ltr">Hi,<div><br></div><div>No, It does not work, I told Cmake to use c++ 20, but it still goes back to c++17. You can see what I get here:<br><br></div><div><a href="https://pastebin.com/5ub18cMU" target="_blank">https://pastebin.com/5ub18cMU</a><br></div><div><br></div><div>my CMakeLists.txt is here:</div><div><br></div><div><a href="https://pastebin.com/3bwMKrWB" target="_blank">https://pastebin.com/3bwMKrWB</a><br></div><div><br></div><div>do you know what could be the problem?</div><div><br></div><div>Cheers.</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, May 7, 2019 at 2:33 AM Mateusz Loskot <<a href="mailto:mateusz@loskot.net">mateusz@loskot.net</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">On Tue, 7 May 2019 at 01:15, Angel Campoverde<br>
<<a href="mailto:campoverdeangelf@gmail.com" target="_blank">campoverdeangelf@gmail.com</a>> wrote:<br>
><br>
> I am looking at:<br>
><br>
> <a href="https://cmake.org/cmake/help/v3.14/prop_tgt/CXX_STANDARD.html" rel="noreferrer" target="_blank">https://cmake.org/cmake/help/v3.14/prop_tgt/CXX_STANDARD.html</a><br>
><br>
> and I see that I can pass 20, for c++20. However I do not have that in my compiler,<br>
> I only have c++2a and gnu++2a, this means that CMake goes back to c++17<br>
<br>
No, it doesn't mean that.<br>
<br>
The valid values documented for CXX_STANDARD are CMake generalisation<br>
and not what is directly passed via -std= or /std: or whatever option<br>
your compiler uses.<br>
<br>
If you run this cmake command<br>
cmake -DCMAKE_CXX_STANDARD=20 -DCMAKE_CXX_EXTENSIONS=OFF ..<br>
and then<br>
VERBOSE=1 make<br>
you will clearly see that CMake generated the compiler<br>
command lines with -std=c++2a<br>
<br>
IFF, you are using version of GCC or clang that supports c++2a, obviously<br>
(i.e. GCC 8/clang 6 or later. I'm not entirely confident about clang)<br>
<br>
Best regards,<br>
-- <br>
Mateusz Loskot, <a href="http://mateusz.loskot.net" rel="noreferrer" target="_blank">http://mateusz.loskot.net</a><br>
-- <br>
<br>
Powered by <a href="http://www.kitware.com" rel="noreferrer" target="_blank">www.kitware.com</a><br>
<br>
Please keep messages on-topic and check the CMake FAQ at: <a href="http://www.cmake.org/Wiki/CMake_FAQ" rel="noreferrer" target="_blank">http://www.cmake.org/Wiki/CMake_FAQ</a><br>
<br>
Kitware offers various services to support the CMake community. For more information on each offering, please visit:<br>
<br>
CMake Support: <a href="http://cmake.org/cmake/help/support.html" rel="noreferrer" target="_blank">http://cmake.org/cmake/help/support.html</a><br>
CMake Consulting: <a href="http://cmake.org/cmake/help/consulting.html" rel="noreferrer" target="_blank">http://cmake.org/cmake/help/consulting.html</a><br>
CMake Training Courses: <a href="http://cmake.org/cmake/help/training.html" rel="noreferrer" target="_blank">http://cmake.org/cmake/help/training.html</a><br>
<br>
Visit other Kitware open-source projects at <a href="http://www.kitware.com/opensource/opensource.html" rel="noreferrer" target="_blank">http://www.kitware.com/opensource/opensource.html</a><br>
<br>
Follow this link to subscribe/unsubscribe:<br>
<a href="https://cmake.org/mailman/listinfo/cmake" rel="noreferrer" target="_blank">https://cmake.org/mailman/listinfo/cmake</a><br>
</blockquote></div>