// bslmf_ismemberpointer.h -*-C++-*- #ifndef INCLUDED_BSLMF_ISMEMBERPOINTER #define INCLUDED_BSLMF_ISMEMBERPOINTER #include <bsls_ident.h> BSLS_IDENT("$Id: $") //@PURPOSE: Provide a compile-time check for non-static member pointer types. // //@CLASSES: // bsl::is_member_pointer: standard meta-function for member pointer types // bsl::is_member_pointer_v: the result value of the standard meta-function // //@SEE_ALSO: bslmf_ismemberfunctionpointer, bslmf_ismemberobjectpointer // //@DESCRIPTION: This component defines a meta-function, // 'bsl::is_member_pointer' and a template variable 'bsl::is_member_pointer_v', // that represents the result value of the 'bsl::is_member_pointer' // meta-function, that may be used to query whether a type is a pointer to // non-static member type. // // 'bsl::is_member_pointer' meets the requirements of the 'is_member_pointer' // template defined in the C++11 standard [meta.unary.comp]. // // Note that the template variable 'is_member_pointer_v' is defined in the // C++17 standard as an inline variable. If the current compiler supports the // inline variable C++17 compiler feature, 'bsl::is_member_pointer_v' is // defined as an 'inline constexpr bool' variable. Otherwise, if the compiler // supports the variable templates C++14 compiler feature, // 'bsl::is_member_pointer_v' is defined as a non-inline 'constexpr bool' // variable. See 'BSLS_COMPILERFEATURES_SUPPORT_INLINE_VARIABLES' and // 'BSLS_COMPILERFEATURES_SUPPORT_VARIABLE_TEMPLATES' macros in // bsls_compilerfeatures component for details. // ///Usage ///----- // In this section we show intended use of this component. // ///Example 1: Verify Member Pointer Types /// - - - - - - - - - - - - - - - - - - - // Suppose that we want to assert whether a set of types are member pointer // types. // // First, we create a user-defined type 'MyStruct': //.. // struct MyStruct // { // }; //.. // Now, we create three 'typedef's -- a member object pointer type, a member // function pointer type and a general function pointer type: //.. // typedef int MyStruct::* DataMemPtr; // typedef int (MyStruct::*MyStructMethodPtr) (); // typedef int (*MyFunctionPtr) (); //.. // Finally, we instantiate the 'bsl::is_member_pointer' template for various // types and assert the 'value' static data member of each instantiation: //.. // assert(false == bsl::is_member_pointer<int*>::value); // assert(false == bsl::is_member_pointer<MyFunctionPtr>::value); // assert(true == bsl::is_member_pointer<DataMemPtr>::value); // assert(true == bsl::is_member_pointer<MyStructMethodPtr>::value); //.. // Note that if the current compiler supports the variable templates C++14 // feature then we can re-write the snippet of code above using the // 'bsl::is_member_pointer_v' variable as follows: //.. //#ifdef BSLS_COMPILERFEATURES_SUPPORT_VARIABLE_TEMPLATES // assert(false == bsl::is_member_pointer_v<int*>); // assert(false == bsl::is_member_pointer_v<MyFunctionPtr>); // assert(true == bsl::is_member_pointer_v<DataMemPtr>); // assert(true == bsl::is_member_pointer_v<MyStructMethodPtr>); //#endif //.. #include <bslscm_version.h> #include <bslmf_integralconstant.h> #include <bsls_compilerfeatures.h> #include <bsls_keyword.h> #include <bsls_platform.h> #ifndef BDE_DONT_ALLOW_TRANSITIVE_INCLUDES #include <bslmf_ismemberfunctionpointer.h> #include <bslmf_ismemberobjectpointer.h> #endif namespace bsl { // ======================== // struct is_member_pointer // ======================== template <class t_TYPE> struct is_member_pointer : false_type { // This 'struct' template implements the 'is_member_pointer' meta-function // defined in the C++11 standard [meta.unary.comp] to determine if the // (template parameter) 't_TYPE' is a member pointer type. This 'struct' // derives from 'bsl::true_type' if the 't_TYPE' is a member pointer type, // and from 'bsl::false_type' otherwise. Additional specializations are // provided below to give the correct answer in all cases. }; template <class t_TARGET_TYPE, class t_HOST_TYPE> struct is_member_pointer<t_TARGET_TYPE t_HOST_TYPE::*> : true_type { // This partial specialization provides the 'true_type' result for a // (cv-unqualified) pointer-to-member type. Note that additional partial // specializations are required to handle the cv-qualified cases. }; template <class t_TARGET_TYPE, class t_HOST_TYPE> struct is_member_pointer<t_TARGET_TYPE t_HOST_TYPE::*const> : true_type { // This partial specialization provides the 'true_type' result for a // 'const'-qualified pointer-to-member type. }; template <class t_TARGET_TYPE, class t_HOST_TYPE> struct is_member_pointer<t_TARGET_TYPE t_HOST_TYPE::*volatile> : true_type { // This partial specialization provides the 'true_type' result for a // 'volatile'-qualified pointer-to-member type. }; template <class t_TARGET_TYPE, class t_HOST_TYPE> struct is_member_pointer<t_TARGET_TYPE t_HOST_TYPE::*const volatile> : true_type { // This partial specialization provides the 'true_type' result for a // 'const volatile'-qualified pointer-to-member type. }; #ifdef BSLS_COMPILERFEATURES_SUPPORT_VARIABLE_TEMPLATES template <class t_TYPE> BSLS_KEYWORD_INLINE_VARIABLE constexpr bool is_member_pointer_v = is_member_pointer<t_TYPE>::value; // This template variable represents the result value of the // 'bsl::is_member_pointer' meta-function. #endif #if defined(BSLS_PLATFORM_CMP_MSVC) \ && BSLS_PLATFORM_CMP_VERSION < 1910 \ &&!((BSLS_PLATFORM_CMP_VERSION == 1900) && defined(BSLS_PLATFORM_CPU_64_BIT)) // MSVC 2013 (and earlier) has two bugs that affect this component. First, // it does not match partial specializations for cv-qualified pointer-to-member // types, requiring a general stripping of cv-qualifiers for all types to get // the right result. Secondly, pointer-to-cv-qualified-member-function fails // to match the partial specialization at all, so fall back on trying to match // a member function with exactly the right signature using variadic templates, // which apparently does work. Note that this bug also appears to affect the // MSVC 2015 compiler, but only for 32-bit builds. template <class t_TYPE> struct is_member_pointer<const t_TYPE> : is_member_pointer<t_TYPE>::type { // The 'const'-qualified (template parameter) 't_TYPE' is a member pointer // if the corresponding unqualified 't_TYPE' is a member pointer. }; template <class t_TYPE> struct is_member_pointer<volatile t_TYPE> : is_member_pointer<t_TYPE>::type { // The 'volatile'-qualified (template parameter) 't_TYPE' is a member // pointer if the corresponding unqualified 't_TYPE' is a member pointer. }; template <class t_TYPE> struct is_member_pointer<const volatile t_TYPE> : is_member_pointer<t_TYPE>::type { // The 'const volatile'-qualified (template parameter) 't_TYPE' is a member // pointer if the corresponding unqualified 't_TYPE' is a member pointer. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...)> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...) const> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...) volatile> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...) const volatile> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...,...)> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...,...) const> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...,...) volatile> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...,...) const volatile> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; #if defined(BSLS_COMPILERFEATURES_SUPPORT_REF_QUALIFIERS) // Only MSVC 2015 32-bit builds get here template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...) &> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...) const &> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...) volatile &> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...) const volatile &> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...,...) &> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...,...) const &> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...,...) volatile &> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...,...) const volatile &> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...) &&> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...) const &&> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...) volatile &&> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...) const volatile &&> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...,...) &&> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...,...) const &&> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...,...) volatile &&> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; template <class RESULT, class HOST, class... ARGS> struct is_member_pointer<RESULT (HOST::*)(ARGS...,...) const volatile &&> : true_type { // This partial specialization for non-cv-qualified pointer-to-member types // derives from 'true_type' if the specified (template parameter) 'type' is // a function type. }; #endif // Reference-qualifier support for MSVC 2015 #endif // MSVC workarounds } // close namespace bsl #endif // ---------------------------------------------------------------------------- // Copyright 2013 Bloomberg Finance L.P. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. // ----------------------------- END-OF-FILE ----------------------------------