The comment above the definition of __cpp_transactional_memory suggests that 201500 was meant to be used. Currently, gcc advertises support for whatever transactional_memory features get standardized the next 86 years... It probably can't be corrected to 201500 if there's existing code that does the __cpp_transactional_memory >= 201505 check, but OTOH setting it to 201505 isn't ideal either.
Author: jakub Date: Wed Jun 6 17:55:39 2018 New Revision: 261242 URL: https://gcc.gnu.org/viewcvs?rev=261242&root=gcc&view=rev Log: PR c++/86068 * c-cppbuiltin.c (c_cpp_builtins): Fix a typo, set __cpp_transactional_memory to 201500 instead of 210500. * include/bits/c++config: Check __cpp_transactional_memory >= 201500L rather than __cpp_transactional_memory >= 201505L. Modified: trunk/gcc/c-family/ChangeLog trunk/gcc/c-family/c-cppbuiltin.c trunk/libstdc++-v3/ChangeLog trunk/libstdc++-v3/include/bits/c++config
The page https://gcc.gnu.org/projects/cxx-status.html probably needs to be updated to say __cpp_transactional_memory >= 201500.
Jakub: Can the bug be marked as resolved? Or please update Known to work.
Fixed.