// bslmf_ismemberfunctionpointer.h -*-C++-*- #ifndef INCLUDED_BSLMF_ISMEMBERFUNCTIONPOINTER #define INCLUDED_BSLMF_ISMEMBERFUNCTIONPOINTER #include <bsls_ident.h> BSLS_IDENT("$Id: $") //@PURPOSE: Provide a compile-time check for member function pointer types. // //@CLASSES: // bsl::is_member_function_pointer: standard meta-function // bsl::is_member_function_pointer_v: the result value of the meta-function // //@SEE_ALSO: bslmf_memberfunctionpointertraits, bslmf_ismemberobjectpointer // //@DESCRIPTION: This component defines a meta-function, // 'bsl::is_member_function_pointer' and a template variable // 'bsl::is_member_function_pointer_v', that represents the result value of the // 'bsl::is_member_function_pointer' meta-function, that may be used to query // whether a type is a pointer to non-static member function type. // // 'bsl::is_member_function_pointer' meets the requirements of the // 'is_member_function_pointer' template defined in the C++11 standard // [meta.unary.cat]. // // Note that, in order to support the widest range of compilers, this // component depends on bslmf_memberfunctionpointertraits, which does not // support member functions with C-style (varargs) elipses. Thus, // 'bsl::is_member_function_pointer' will return a false negative if invoked // on a pointer to such a member. // // Note that the template variable 'is_member_function_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_function_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_function_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 Function Pointer Types ///- - - - - - - - - - - - - - - - - - - - - - - - // Suppose that we want to assert whether a set of types are pointers to // non-static member function types. // // First, we create a user-defined type 'MyStruct': //.. // struct MyStruct // { // }; //.. // Now, we create two 'typedef's -- a function pointer type and a member // function pointer type: //.. // typedef int (MyStruct::*MyStructMethodPtr) (); // typedef int (*MyFunctionPtr) (); //.. // Finally, we instantiate the 'bsl::is_member_function_pointer' template for // each of the 'typedef's and assert the 'value' static data member of each // instantiation: //.. // assert(false == bsl::is_member_function_pointer<MyFunctionPtr >::value); // assert(true == bsl::is_member_function_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_function_pointer_v' variable as follows: //.. //#ifdef BSLS_COMPILERFEATURES_SUPPORT_VARIABLE_TEMPLATES // assert(false == bsl::is_member_function_pointer_v<MyFunctionPtr >); // assert(true == bsl::is_member_function_pointer_v<MyStructMethodPtr>); //#endif //.. #include <bslscm_version.h> #include <bslmf_integralconstant.h> #include <bslmf_isfunction.h> #include <bsls_compilerfeatures.h> #include <bsls_keyword.h> #include <bsls_platform.h> #ifndef BDE_DONT_ALLOW_TRANSITIVE_INCLUDES #include <bslmf_memberfunctionpointertraits.h> #endif #if !defined(BSLS_PLATFORM_CMP_MSVC) \ || BSLS_PLATFORM_CMP_VERSION > 1900 \ ||((BSLS_PLATFORM_CMP_VERSION == 1900) && defined(BSLS_PLATFORM_CPU_64_BIT)) namespace bsl { // ================================= // struct is_member_function_pointer // ================================= template <class t_TYPE> struct is_member_function_pointer : false_type { // This 'struct' template implements the 'is_member_function_pointer' // meta-function defined in the C++11 standard [meta.unary.cat] to // determine if the (template parameter) 't_TYPE' is a pointer to // non-static member function type. This 'struct' derives from // 'bsl::true_type' if the 't_TYPE' is a pointer to non-static member // function type, and from 'bsl::false_type' otherwise. Additional // specializations are provided below to give the correct answer in all // cases. }; template <class t_TYPE, class t_CLASS> struct is_member_function_pointer<t_TYPE t_CLASS::*> : bsl::is_function<t_TYPE>::type { // This partial specialization for all non-cv-qualified pointer-to-member // types derives from 'true_type' if the specified (template parameter) // 'type' is a function type, and from 'false_type' otherwise. }; template <class t_TYPE, class t_CLASS> struct is_member_function_pointer<t_TYPE t_CLASS::*const> : bsl::is_function<t_TYPE>::type { // This partial specialization for all 'const'-qualified pointer-to-member // types derives from 'true_type' if the specified (template parameter) // 'type' is a function type, and from 'false_type' otherwise. }; template <class t_TYPE, class t_CLASS> struct is_member_function_pointer<t_TYPE t_CLASS::*volatile> : bsl::is_function<t_TYPE>::type { // This partial specialization for all 'volatile'-qualified // pointer-to-member types derives from 'true_type' if the specified // (template parameter) 'type' is a function type, and from 'false_type' // otherwise. }; template <class t_TYPE, class t_CLASS> struct is_member_function_pointer<t_TYPE t_CLASS::*const volatile> : bsl::is_function<t_TYPE>::type { // This partial specialization for all 'const volatile'-qualified // pointer-to-member types derives from 'true_type'. }; #ifdef BSLS_COMPILERFEATURES_SUPPORT_VARIABLE_TEMPLATES template <class t_TYPE> BSLS_KEYWORD_INLINE_VARIABLE constexpr bool is_member_function_pointer_v = is_member_function_pointer<t_TYPE>::value; // This variable template represents the result value of the // 'bsl::is_member_function_pointer' meta-function. #endif } // close namespace bsl #else // MSVC 2013 workaround namespace bsl { // ================================= // struct is_member_function_pointer // ================================= template <class t_TYPE> struct is_member_function_pointer : false_type { // This 'struct' template implements the 'is_member_function_pointer' // meta-function defined in the C++11 standard [meta.unary.cat] to // determine if the (template parameter) 't_TYPE' is a pointer to // non-static member function type. This 'struct' derives from // 'bsl::true_type' if the 't_TYPE' is a pointer to non-static member // function type, and from 'bsl::false_type' otherwise. Additional // specializations are provided below to give the correct answer in all // cases. }; template <class t_TYPE> struct is_member_function_pointer<const t_TYPE> : is_member_function_pointer<t_TYPE>::type { }; template <class t_TYPE> struct is_member_function_pointer<volatile t_TYPE> : is_member_function_pointer<t_TYPE>::type { }; template <class t_TYPE> struct is_member_function_pointer<const volatile t_TYPE> : is_member_function_pointer<t_TYPE>::type { }; template <class RESULT, class HOST, class... ARGS> struct is_member_function_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_function_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_function_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_function_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_function_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_function_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_function_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_function_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_function_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_function_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_function_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_function_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_function_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_function_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_function_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_function_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_function_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_function_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_function_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_function_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_function_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_function_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_function_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_function_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 #ifdef BSLS_COMPILERFEATURES_SUPPORT_VARIABLE_TEMPLATES template <class t_TYPE> BSLS_KEYWORD_INLINE_VARIABLE constexpr bool is_member_function_pointer_v = is_member_function_pointer<t_TYPE>::value; // This variable template represents the result value of the // 'bsl::is_member_function_pointer' meta-function. #endif } // close namespace bsl #endif // MSVC 2013 workaround #endif // ---------------------------------------------------------------------------- // Copyright 2013-2018 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 ----------------------------------