Re: [boost] [thread] Can Boost.Thread use Boost.Atomic withoutfalling on a compatibility issue?

Howard Hinnant wrote:

There are a couple of places in libc++ that need to be retrofitted to use <atomic>. In the cases where that retrofit is in a header (i.e. call_once), the retrofit will currently need to be protected by __has_feature(cxx_atomic) as clang shuts this feature off in C++03 mode.

Not very on-topic, but... what does it mean that clang shuts the feature off? I see in <atomic> that you issue an #error when !__has_feature(cxx_atomic), but what would happen if this is removed? Don't the C11 intrinsics work regardless?