Documentation about C++ Concepts

[Akim Demaille]

Hi!

I’m looking for a #if guard to enable/disable code using concepts-lite.  The compiler version does not suffice, as it depends on -std=c++1z.  Also, the documentation about concepts seems to be about the previous attempts at concepts.

https://gcc.gnu.org/onlinedocs/gcc/C_002b_002b-Concepts.html#C_002b_002b-Concepts

And actually, I did not find the documentation for c++1z, nor even -std=c++14.

https://gcc.gnu.org/onlinedocs/gcc/Standards.html#index-std-60

Finally, one would expect to see documentation about -std in "Options Controlling C++ Dialect", since the corresponding about C documents -std for C.

https://gcc.gnu.org/onlinedocs/gcc/C_002b_002b-Dialect-Options.html#C_002b_002b-Dialect-Options

Thanks!