On 10 November 2014 16:46, Andrew Haley wrote: > What do you believe a __builtin does but a standard atomic does not do? Both C11 and C++11 only support atomic operations on their "atomic types" and there's no atomic float type (although I'm not sure the builtins should really support floating point types either). The atomic types are also incompatible between C11, as in C they use the _Atomic qualifier and in C++ they are struct types. So although you can write this in both languages, it doesn't have the same meaning: atomic_int i; atomic_store(&i, 1); (Because WG14 made a last-minute change to the design that very deliberately allowed compatibility between the languages.)
