16 Library introduction [library]

Unless explicitly stated otherwise, it is unspecified whether any class described in [support] through [exec] and [depr] is a trivially copyable class, a standard-layout class, or an implicit-lifetime class ([class.prop]).

Unless explicitly stated otherwise, it is unspecified whether any class for which trivial relocation (i.e., the effects of trivially_relocate ([obj.lifetime])) would be semantically equivalent to move-construction of the destination object followed by destruction of the source object is a trivially relocatable class ([class.prop]).

Unless explicitly stated otherwise, it is unspecified whether a class C is a replaceable class ([class.prop]) if assigning an xvalue a of type C to an object b of type C is semantically equivalent to destroying b and then constructing from a in b's place.