The standard library that ships with GCC 5 makes use of three new type trait primitives: __is_trivially_copyable __is_trivially_constructible __is_trivially_assignable I couldn't find documentation of these primitives here [1]. Am I looking in the wrong place, or are they undocumented? Thanks, Nate [1] https://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html