diff options
Diffstat (limited to 'absl/types')
| -rw-r--r-- | absl/types/internal/variant.h | 15 | ||||
| -rw-r--r-- | absl/types/variant.h | 28 |
2 files changed, 27 insertions, 16 deletions
diff --git a/absl/types/internal/variant.h b/absl/types/internal/variant.h index 3414c91..7db5e05 100644 --- a/absl/types/internal/variant.h +++ b/absl/types/internal/variant.h @@ -579,12 +579,9 @@ struct VariantCoreAccess { self.index_ = other.index(); } + // Access a variant alternative, assuming the index is correct. template <std::size_t I, class Variant> static VariantAccessResult<I, Variant> Access(Variant&& self) { - if (ABSL_PREDICT_FALSE(self.index_ != I)) { - TypedThrowBadVariantAccess<VariantAccessResult<I, Variant>>(); - } - // This cast instead of invocation of AccessUnion with an rvalue is a // workaround for msvc. Without this there is a runtime failure when dealing // with rvalues. @@ -593,6 +590,16 @@ struct VariantCoreAccess { variant_internal::AccessUnion(self.state_, SizeT<I>())); } + // Access a variant alternative, throwing if the index is incorrect. + template <std::size_t I, class Variant> + static VariantAccessResult<I, Variant> CheckedAccess(Variant&& self) { + if (ABSL_PREDICT_FALSE(self.index_ != I)) { + TypedThrowBadVariantAccess<VariantAccessResult<I, Variant>>(); + } + + return Access<I>(absl::forward<Variant>(self)); + } + // The implementation of the move-assignment operation for a variant. template <class VType> struct MoveAssignVisitor { diff --git a/absl/types/variant.h b/absl/types/variant.h index 55017ae..fd1d49a 100644 --- a/absl/types/variant.h +++ b/absl/types/variant.h @@ -290,7 +290,7 @@ constexpr bool holds_alternative(const variant<Types...>& v) noexcept { // Overload for getting a variant's lvalue by type. template <class T, class... Types> constexpr T& get(variant<Types...>& v) { // NOLINT - return variant_internal::VariantCoreAccess::Access< + return variant_internal::VariantCoreAccess::CheckedAccess< variant_internal::IndexOf<T, Types...>::value>(v); } @@ -298,14 +298,14 @@ constexpr T& get(variant<Types...>& v) { // NOLINT // Note: `absl::move()` is required to allow use of constexpr in C++11. template <class T, class... Types> constexpr T&& get(variant<Types...>&& v) { - return variant_internal::VariantCoreAccess::Access< + return variant_internal::VariantCoreAccess::CheckedAccess< variant_internal::IndexOf<T, Types...>::value>(absl::move(v)); } // Overload for getting a variant's const lvalue by type. template <class T, class... Types> constexpr const T& get(const variant<Types...>& v) { - return variant_internal::VariantCoreAccess::Access< + return variant_internal::VariantCoreAccess::CheckedAccess< variant_internal::IndexOf<T, Types...>::value>(v); } @@ -313,7 +313,7 @@ constexpr const T& get(const variant<Types...>& v) { // Note: `absl::move()` is required to allow use of constexpr in C++11. template <class T, class... Types> constexpr const T&& get(const variant<Types...>&& v) { - return variant_internal::VariantCoreAccess::Access< + return variant_internal::VariantCoreAccess::CheckedAccess< variant_internal::IndexOf<T, Types...>::value>(absl::move(v)); } @@ -321,7 +321,7 @@ constexpr const T&& get(const variant<Types...>&& v) { template <std::size_t I, class... Types> constexpr variant_alternative_t<I, variant<Types...>>& get( variant<Types...>& v) { // NOLINT - return variant_internal::VariantCoreAccess::Access<I>(v); + return variant_internal::VariantCoreAccess::CheckedAccess<I>(v); } // Overload for getting a variant's rvalue by index. @@ -329,14 +329,14 @@ constexpr variant_alternative_t<I, variant<Types...>>& get( template <std::size_t I, class... Types> constexpr variant_alternative_t<I, variant<Types...>>&& get( variant<Types...>&& v) { - return variant_internal::VariantCoreAccess::Access<I>(absl::move(v)); + return variant_internal::VariantCoreAccess::CheckedAccess<I>(absl::move(v)); } // Overload for getting a variant's const lvalue by index. template <std::size_t I, class... Types> constexpr const variant_alternative_t<I, variant<Types...>>& get( const variant<Types...>& v) { - return variant_internal::VariantCoreAccess::Access<I>(v); + return variant_internal::VariantCoreAccess::CheckedAccess<I>(v); } // Overload for getting a variant's const rvalue by index. @@ -344,7 +344,7 @@ constexpr const variant_alternative_t<I, variant<Types...>>& get( template <std::size_t I, class... Types> constexpr const variant_alternative_t<I, variant<Types...>>&& get( const variant<Types...>&& v) { - return variant_internal::VariantCoreAccess::Access<I>(absl::move(v)); + return variant_internal::VariantCoreAccess::CheckedAccess<I>(absl::move(v)); } // get_if() @@ -362,8 +362,10 @@ constexpr const variant_alternative_t<I, variant<Types...>>&& get( template <std::size_t I, class... Types> constexpr absl::add_pointer_t<variant_alternative_t<I, variant<Types...>>> get_if(variant<Types...>* v) noexcept { - return (v != nullptr && v->index() == I) ? std::addressof(absl::get<I>(*v)) - : nullptr; + return (v != nullptr && v->index() == I) + ? std::addressof( + variant_internal::VariantCoreAccess::Access<I>(*v)) + : nullptr; } // Overload for getting a pointer to the const value stored in the given @@ -371,8 +373,10 @@ get_if(variant<Types...>* v) noexcept { template <std::size_t I, class... Types> constexpr absl::add_pointer_t<const variant_alternative_t<I, variant<Types...>>> get_if(const variant<Types...>* v) noexcept { - return (v != nullptr && v->index() == I) ? std::addressof(absl::get<I>(*v)) - : nullptr; + return (v != nullptr && v->index() == I) + ? std::addressof( + variant_internal::VariantCoreAccess::Access<I>(*v)) + : nullptr; } // Overload for getting a pointer to the value stored in the given variant by |