libstdc++-v3/ChangeLog:
* include/std/variant (__variant::__get(in_place_index_t<N>, U&&)):
Rename to __get_n and remove first argument. Replace pair of
overloads with a single function using 'if constexpr'.
(__variant::__get(Variant&&)): Adjust to use __get_n.
Tested powerpc64le-linux. Committed to trunk.
commit 4f87d4c5aec9a1eaca7be61e5c8aab4d6e61b1d8
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Thu Oct 14 20:37:38 2021
libstdc++: Simplify variant access functions
libstdc++-v3/ChangeLog:
* include/std/variant (__variant::__get(in_place_index_t<N>, U&&)):
Rename to __get_n and remove first argument. Replace pair of
overloads with a single function using 'if constexpr'.
(__variant::__get(Variant&&)): Adjust to use __get_n.
diff --git a/libstdc++-v3/include/std/variant b/libstdc++-v3/include/std/variant
index 6377b6731ea..b85a89d0b7b 100644
--- a/libstdc++-v3/include/std/variant
+++ b/libstdc++-v3/include/std/variant
@@ -279,27 +279,26 @@ namespace __variant
__gnu_cxx::__aligned_membuf<_Type> _M_storage;
};
- template<typename _Union>
- constexpr decltype(auto)
- __get(in_place_index_t<0>, _Union&& __u) noexcept
- { return std::forward<_Union>(__u)._M_first._M_get(); }
-
template<size_t _Np, typename _Union>
constexpr decltype(auto)
- __get(in_place_index_t<_Np>, _Union&& __u) noexcept
+ __get_n(_Union&& __u) noexcept
{
- return __variant::__get(in_place_index<_Np-1>,
- std::forward<_Union>(__u)._M_rest);
+ if constexpr (_Np == 0)
+ return std::forward<_Union>(__u)._M_first._M_get();
+ else if constexpr (_Np == 1)
+ return std::forward<_Union>(__u)._M_rest._M_first._M_get();
+ else if constexpr (_Np == 2)
+ return std::forward<_Union>(__u)._M_rest._M_rest._M_first._M_get();
+ else
+ return __variant::__get_n<_Np - 3>(
+ std::forward<_Union>(__u)._M_rest._M_rest._M_rest);
}
// Returns the typed storage for __v.
template<size_t _Np, typename _Variant>
constexpr decltype(auto)
__get(_Variant&& __v) noexcept
- {
- return __variant::__get(std::in_place_index<_Np>,
- std::forward<_Variant>(__v)._M_u);
- }
+ { return __variant::__get_n<_Np>(std::forward<_Variant>(__v)._M_u); }
template<typename... _Types>
struct _Traits
