Tested powerpc64le-linux, pushed to trunk.
-- >8 --
libstdc++-v3/ChangeLog:
* include/std/variant (_Build_FUN::_S_fun): Define fallback case
as deleted.
(__accepted_index, _Extra_visit_slot_needed): Replace class
templates with variable templates.
---
libstdc++-v3/include/std/variant | 43 ++++++++++++++++----------------
1 file changed, 21 insertions(+), 22 deletions(-)
diff --git a/libstdc++-v3/include/std/variant b/libstdc++-v3/include/std/variant
index c5f25ef6b47..5ff1e3edcdf 100644
--- a/libstdc++-v3/include/std/variant
+++ b/libstdc++-v3/include/std/variant
@@ -764,7 +764,7 @@ namespace __variant
{
// This function means 'using _Build_FUN<I, T, Ti>::_S_fun;' is valid,
// but only static functions will be considered in the call below.
- void _S_fun();
+ void _S_fun() = delete;
};
// "... for which Ti x[] = {std::forward<T>(t)}; is well-formed."
@@ -795,29 +795,28 @@ namespace __variant
// The index selected for FUN(std::forward<T>(t)), or variant_npos if none.
template<typename _Tp, typename _Variant, typename = void>
- struct __accepted_index
- : integral_constant<size_t, variant_npos>
- { };
+ inline constexpr size_t
+ __accepted_index = variant_npos;
template<typename _Tp, typename _Variant>
- struct __accepted_index<_Tp, _Variant, void_t<_FUN_type<_Tp, _Variant>>>
- : _FUN_type<_Tp, _Variant>
- { };
+ inline constexpr size_t
+ __accepted_index<_Tp, _Variant, void_t<_FUN_type<_Tp, _Variant>>>
+ = _FUN_type<_Tp, _Variant>::value;
- template <typename _Maybe_variant_cookie, typename _Variant>
- struct _Extra_visit_slot_needed
- {
- template <typename> struct _Variant_never_valueless;
+ template<typename _Maybe_variant_cookie, typename _Variant,
+ typename = __remove_cvref_t<_Variant>>
+ inline constexpr bool
+ __extra_visit_slot_needed = false;
- template <typename... _Types>
- struct _Variant_never_valueless<variant<_Types...>>
- : bool_constant<__variant::__never_valueless<_Types...>()> {};
+ template<typename _Var, typename... _Types>
+ inline constexpr bool
+ __extra_visit_slot_needed<__variant_cookie, _Var, variant<_Types...>>
+ = !__variant::__never_valueless<_Types...>();
- static constexpr bool value =
- (is_same_v<_Maybe_variant_cookie, __variant_cookie>
- || is_same_v<_Maybe_variant_cookie, __variant_idx_cookie>)
- && !_Variant_never_valueless<__remove_cvref_t<_Variant>>::value;
- };
+ template<typename _Var, typename... _Types>
+ inline constexpr bool
+ __extra_visit_slot_needed<__variant_idx_cookie, _Var, variant<_Types...>>
+ = !__variant::__never_valueless<_Types...>();
// Used for storing a multi-dimensional vtable.
template<typename _Tp, size_t... _Dimensions>
@@ -874,7 +873,7 @@ namespace __variant
using _Variant = typename _Nth_type<__index, _Variants...>::type;
static constexpr int __do_cookie =
- _Extra_visit_slot_needed<_Ret, _Variant>::value ? 1 : 0;
+ __extra_visit_slot_needed<_Ret, _Variant> ? 1 : 0;
using _Tp = _Ret(*)(_Visitor, _Variants...);
@@ -953,7 +952,7 @@ namespace __variant
_S_apply_all_alts(_Array_type& __vtable,
std::index_sequence<__var_indices...>)
{
- if constexpr (_Extra_visit_slot_needed<_Result_type, _Next>::value)
+ if constexpr (__extra_visit_slot_needed<_Result_type, _Next>)
(_S_apply_single_alt<true, __var_indices>(
__vtable._M_arr[__var_indices + 1],
&(__vtable._M_arr[0])), ...);
@@ -1372,7 +1371,7 @@ namespace __variant
template<typename _Tp>
static constexpr size_t __accepted_index
- = __detail::__variant::__accepted_index<_Tp, variant>::value;
+ = __detail::__variant::__accepted_index<_Tp, variant>;
template<size_t _Np, typename = enable_if_t<(_Np < sizeof...(_Types))>>
using __to_type = typename _Nth_type<_Np, _Types...>::type;
--
2.36.1
