Specialization of ResultType for when t_FUNC::result_type exists, i.e., when the C++ standard idiom for result_type is used.
Synopsis
Declared in <bslmf_resulttype.h>
template<
class t_FUNC,
class t_FALLBACK>
struct ResultType<t_FUNC, t_FALLBACK, bsl::void_t<t_FUNC::result_type>>;