diff options
Diffstat (limited to 'absl/base/internal/invoke.h')
-rw-r--r-- | absl/base/internal/invoke.h | 131 |
1 files changed, 32 insertions, 99 deletions
diff --git a/absl/base/internal/invoke.h b/absl/base/internal/invoke.h index ab5ad910..c4eceebd 100644 --- a/absl/base/internal/invoke.h +++ b/absl/base/internal/invoke.h @@ -18,19 +18,16 @@ // [func.require] // Define INVOKE (f, t1, t2, ..., tN) as follows: // 1. (t1.*f)(t2, ..., tN) when f is a pointer to a member function of a class T -// and is_base_of_v<T, remove_reference_t<decltype(t1)>> is true; -// 2. (t1.get().*f)(t2, ..., tN) when f is a pointer to a member function of a -// class T and remove_cvref_t<decltype(t1)> is a specialization of -// reference_wrapper; -// 3. ((*t1).*f)(t2, ..., tN) when f is a pointer to a member function of a -// class T and t1 does not satisfy the previous two items; -// 4. t1.*f when N == 1 and f is a pointer to data member of a class T and -// is_base_of_v<T, remove_reference_t<decltype(t1)>> is true; -// 5. t1.get().*f when N == 1 and f is a pointer to data member of a class T and -// remove_cvref_t<decltype(t1)> is a specialization of reference_wrapper; -// 6. (*t1).*f when N == 1 and f is a pointer to data member of a class T and t1 -// does not satisfy the previous two items; -// 7. f(t1, t2, ..., tN) in all other cases. +// and t1 is an object of type T or a reference to an object of type T or a +// reference to an object of a type derived from T; +// 2. ((*t1).*f)(t2, ..., tN) when f is a pointer to a member function of a +// class T and t1 is not one of the types described in the previous item; +// 3. t1.*f when N == 1 and f is a pointer to member data of a class T and t1 is +// an object of type T or a reference to an object of type T or a reference +// to an object of a type derived from T; +// 4. (*t1).*f when N == 1 and f is a pointer to member data of a class T and t1 +// is not one of the types described in the previous item; +// 5. f(t1, t2, ..., tN) in all other cases. // // The implementation is SFINAE-friendly: substitution failure within Invoke() // isn't an error. @@ -51,16 +48,7 @@ namespace absl { ABSL_NAMESPACE_BEGIN namespace base_internal { -template <typename T> -struct IsReferenceWrapper : std::false_type {}; -template <typename T> -struct IsReferenceWrapper<std::reference_wrapper<T>> : std::true_type {}; - -template <typename T> -using RemoveCvrefT = - typename std::remove_cv<typename std::remove_reference<T>::type>::type; - -// The seven classes below each implement one of the clauses from the definition +// The five classes below each implement one of the clauses from the definition // of INVOKE. The inner class template Accept<F, Args...> checks whether the // clause is applicable; static function template Invoke(f, args...) does the // invocation. @@ -84,10 +72,9 @@ struct MemFunAndRef : StrippedAccept<MemFunAndRef> { template <typename MemFunType, typename C, typename Obj, typename... Args> struct AcceptImpl<MemFunType C::*, Obj, Args...> - : std::integral_constant< - bool, std::is_base_of< - C, typename std::remove_reference<Obj>::type>::value && - absl::is_function<MemFunType>::value> {}; + : std::integral_constant<bool, std::is_base_of<C, Obj>::value && + absl::is_function<MemFunType>::value> { + }; template <typename MemFun, typename Obj, typename... Args> static decltype((std::declval<Obj>().* @@ -98,41 +85,17 @@ struct MemFunAndRef : StrippedAccept<MemFunAndRef> { } }; -// (t1.get().*f)(t2, ..., tN) when f is a pointer to a member function of a -// class T and remove_cvref_t<decltype(t1)> is a specialization of -// reference_wrapper; -struct MemFunAndRefWrap : StrippedAccept<MemFunAndRefWrap> { - template <typename... Args> - struct AcceptImpl : std::false_type {}; - - template <typename MemFunType, typename C, typename RefWrap, typename... Args> - struct AcceptImpl<MemFunType C::*, RefWrap, Args...> - : std::integral_constant< - bool, IsReferenceWrapper<RemoveCvrefT<RefWrap>>::value && - absl::is_function<MemFunType>::value> {}; - - template <typename MemFun, typename RefWrap, typename... Args> - static decltype((std::declval<RefWrap>().get().* - std::declval<MemFun>())(std::declval<Args>()...)) - Invoke(MemFun&& mem_fun, RefWrap&& ref_wrap, Args&&... args) { - return (std::forward<RefWrap>(ref_wrap).get().* - std::forward<MemFun>(mem_fun))(std::forward<Args>(args)...); - } -}; - // ((*t1).*f)(t2, ..., tN) when f is a pointer to a member function of a -// class T and t1 does not satisfy the previous two items; +// class T and t1 is not one of the types described in the previous item. struct MemFunAndPtr : StrippedAccept<MemFunAndPtr> { template <typename... Args> struct AcceptImpl : std::false_type {}; template <typename MemFunType, typename C, typename Ptr, typename... Args> struct AcceptImpl<MemFunType C::*, Ptr, Args...> - : std::integral_constant< - bool, !std::is_base_of< - C, typename std::remove_reference<Ptr>::type>::value && - !IsReferenceWrapper<RemoveCvrefT<Ptr>>::value && - absl::is_function<MemFunType>::value> {}; + : std::integral_constant<bool, !std::is_base_of<C, Ptr>::value && + absl::is_function<MemFunType>::value> { + }; template <typename MemFun, typename Ptr, typename... Args> static decltype(((*std::declval<Ptr>()).* @@ -143,18 +106,17 @@ struct MemFunAndPtr : StrippedAccept<MemFunAndPtr> { } }; -// t1.*f when N == 1 and f is a pointer to data member of a class T and -// is_base_of_v<T, remove_reference_t<decltype(t1)>> is true; +// t1.*f when N == 1 and f is a pointer to member data of a class T and t1 is +// an object of type T or a reference to an object of type T or a reference +// to an object of a type derived from T. struct DataMemAndRef : StrippedAccept<DataMemAndRef> { template <typename... Args> struct AcceptImpl : std::false_type {}; template <typename R, typename C, typename Obj> struct AcceptImpl<R C::*, Obj> - : std::integral_constant< - bool, std::is_base_of< - C, typename std::remove_reference<Obj>::type>::value && - !absl::is_function<R>::value> {}; + : std::integral_constant<bool, std::is_base_of<C, Obj>::value && + !absl::is_function<R>::value> {}; template <typename DataMem, typename Ref> static decltype(std::declval<Ref>().*std::declval<DataMem>()) Invoke( @@ -163,39 +125,16 @@ struct DataMemAndRef : StrippedAccept<DataMemAndRef> { } }; -// t1.get().*f when N == 1 and f is a pointer to data member of a class T and -// remove_cvref_t<decltype(t1)> is a specialization of reference_wrapper; -struct DataMemAndRefWrap : StrippedAccept<DataMemAndRefWrap> { - template <typename... Args> - struct AcceptImpl : std::false_type {}; - - template <typename R, typename C, typename RefWrap> - struct AcceptImpl<R C::*, RefWrap> - : std::integral_constant< - bool, IsReferenceWrapper<RemoveCvrefT<RefWrap>>::value && - !absl::is_function<R>::value> {}; - - template <typename DataMem, typename RefWrap> - static decltype(std::declval<RefWrap>().get().*std::declval<DataMem>()) - Invoke(DataMem&& data_mem, RefWrap&& ref_wrap) { - return std::forward<RefWrap>(ref_wrap).get().* - std::forward<DataMem>(data_mem); - } -}; - -// (*t1).*f when N == 1 and f is a pointer to data member of a class T and t1 -// does not satisfy the previous two items; +// (*t1).*f when N == 1 and f is a pointer to member data of a class T and t1 +// is not one of the types described in the previous item. struct DataMemAndPtr : StrippedAccept<DataMemAndPtr> { template <typename... Args> struct AcceptImpl : std::false_type {}; template <typename R, typename C, typename Ptr> struct AcceptImpl<R C::*, Ptr> - : std::integral_constant< - bool, !std::is_base_of< - C, typename std::remove_reference<Ptr>::type>::value && - !IsReferenceWrapper<RemoveCvrefT<Ptr>>::value && - !absl::is_function<R>::value> {}; + : std::integral_constant<bool, !std::is_base_of<C, Ptr>::value && + !absl::is_function<R>::value> {}; template <typename DataMem, typename Ptr> static decltype((*std::declval<Ptr>()).*std::declval<DataMem>()) Invoke( @@ -221,18 +160,12 @@ struct Invoker { typedef typename std::conditional< MemFunAndRef::Accept<Args...>::value, MemFunAndRef, typename std::conditional< - MemFunAndRefWrap::Accept<Args...>::value, MemFunAndRefWrap, + MemFunAndPtr::Accept<Args...>::value, MemFunAndPtr, typename std::conditional< - MemFunAndPtr::Accept<Args...>::value, MemFunAndPtr, - typename std::conditional< - DataMemAndRef::Accept<Args...>::value, DataMemAndRef, - typename std::conditional< - DataMemAndRefWrap::Accept<Args...>::value, - DataMemAndRefWrap, - typename std::conditional< - DataMemAndPtr::Accept<Args...>::value, DataMemAndPtr, - Callable>::type>::type>::type>::type>::type>::type - type; + DataMemAndRef::Accept<Args...>::value, DataMemAndRef, + typename std::conditional<DataMemAndPtr::Accept<Args...>::value, + DataMemAndPtr, Callable>::type>::type>:: + type>::type type; }; // The result type of Invoke<F, Args...>. |