On 20 December 2015 at 19:13, Akim Demaille <akim.demaille@xxxxxxxxx> wrote: > Hi! > > I’m looking for a #if guard to enable/disable code using concepts-lite. As required by the Concepts TS, the compiler defines __cpp_concepts when it supports concepts. > The compiler version does not suffice, as it depends on -std=c++1z. For GCC you could test __cplusplus to see if -std=c++1z was used, because Concepts support is always enabled when __cplusplus > 201402L. > 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/C-Dialect-Options.html Also https://gcc.gnu.org/projects/cxx1y.html https://gcc.gnu.org/projects/cxx1z.html > 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 That's the documentation about -std in general, not -std for C. It says "The following options control the dialect of C (or languages derived from C, such as C++, ...)" > Thanks!
