diff options
Diffstat (limited to 'libstdc++-v3/include/bits/funcwrap.h')
| -rw-r--r-- | libstdc++-v3/include/bits/funcwrap.h | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/libstdc++-v3/include/bits/funcwrap.h b/libstdc++-v3/include/bits/funcwrap.h index cf261bc..9db4ab7 100644 --- a/libstdc++-v3/include/bits/funcwrap.h +++ b/libstdc++-v3/include/bits/funcwrap.h @@ -199,7 +199,25 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION }; template<typename _Tp> - using __param_t = __conditional_t<is_scalar_v<_Tp>, _Tp, _Tp&&>; + consteval bool + __pass_by_value() + { + // n.b. sizeof(Incomplete&) is ill-formed for incomplete types, + // so we check is_reference_v first. + if constexpr (is_reference_v<_Tp> || is_scalar_v<_Tp>) + return true; + else + // n.b. we already asserted that types are complete in wrappers, + // avoid triggering additional errors from this function. + if constexpr (std::__is_complete_or_unbounded(__type_identity<_Tp>())) + if constexpr (sizeof(_Tp) <= 2 * sizeof(void*)) + return is_trivially_move_constructible_v<_Tp> + && is_trivially_destructible_v<_Tp>; + return false; + } + + template<typename _Tp> + using __param_t = __conditional_t<__pass_by_value<_Tp>(), _Tp, _Tp&&>; template<bool _Noex, typename _Ret, typename... _Args> using _Invoker = _Base_invoker<_Noex, remove_cv_t<_Ret>, __param_t<_Args>...>; |