bslmf_ismemberfunctionpointer.h

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/// @file bslmf_ismemberfunctionpointer.h
///
/// The content of this file has been pre-processed for Doxygen.
///
 
 
// bslmf_ismemberfunctionpointer.h                                    -*-C++-*-
#ifndef INCLUDED_BSLMF_ISMEMBERFUNCTIONPOINTER
#define INCLUDED_BSLMF_ISMEMBERFUNCTIONPOINTER
 
#include <bsls_ident.h>
BSLS_IDENT("$Id: $")
 
/// @defgroup bslmf_ismemberfunctionpointer bslmf_ismemberfunctionpointer
/// @brief  Provide a compile-time check for member function pointer types.
/// @addtogroup bsl
/// @{
/// @addtogroup bslmf
/// @{
/// @addtogroup bslmf_ismemberfunctionpointer
/// @{
///
/// <h1> Outline </h1>
/// * <a href="#bslmf_ismemberfunctionpointer-purpose"> Purpose</a>
/// * <a href="#bslmf_ismemberfunctionpointer-classes"> Classes </a>
/// * <a href="#bslmf_ismemberfunctionpointer-description"> Description </a>
///   * <a href="#bslmf_ismemberfunctionpointer-usage"> Usage </a>
///     * <a href="#bslmf_ismemberfunctionpointer-example-1-verify-member-function-pointer-types"> Example 1: Verify Member Function Pointer Types </a>
///
/// # Purpose {#bslmf_ismemberfunctionpointer-purpose}
/// Provide a compile-time check for member function pointer types.
///
/// # Classes {#bslmf_ismemberfunctionpointer-classes}
///
/// -  bsl::is_member_function_pointer: standard meta-function
/// -  bsl::is_member_function_pointer_v: the result value of the meta-function
///
/// @see  bslmf_memberfunctionpointertraits, bslmf_ismemberobjectpointer
///
/// # Description {#bslmf_ismemberfunctionpointer-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 {#bslmf_ismemberfunctionpointer-usage}
///
///
/// In this section we show intended use of this component.
///
/// ### Example 1: Verify Member Function Pointer Types {#bslmf_ismemberfunctionpointer-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`:
/// @code
/// struct MyStruct
/// {
/// };
/// @endcode
/// Now, we create two `typedef`s -- a function pointer type and a member
/// function pointer type:
/// @code
/// typedef int (MyStruct::*MyStructMethodPtr) ();
/// typedef int (*MyFunctionPtr) ();
/// @endcode
/// 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:
/// @code
/// assert(false == bsl::is_member_function_pointer<MyFunctionPtr    >::value);
/// assert(true  == bsl::is_member_function_pointer<MyStructMethodPtr>::value);
/// @endcode
/// 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:
/// @code
/// #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
/// @endcode
/// @}
/** @} */
/** @} */
 
/** @addtogroup bsl
 * @{
 */
/** @addtogroup bslmf
 * @{
 */
/** @addtogroup bslmf_ismemberfunctionpointer
 * @{
 */
 
#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
                       // =================================
 
/// 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 : false_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::*>
: 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::*const>
: 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::*volatile>
: bsl::is_function<t_TYPE>::type {
};
 
/// This partial specialization for all `const volatile`-qualified
/// pointer-to-member types derives from `true_type`.
template <class t_TYPE, class t_CLASS>
struct is_member_function_pointer<t_TYPE t_CLASS::*const volatile>
: bsl::is_function<t_TYPE>::type {
};
 
#ifdef BSLS_COMPILERFEATURES_SUPPORT_VARIABLE_TEMPLATES
/// This variable template represents the result value of the
/// `bsl::is_member_function_pointer` meta-function.
template <class t_TYPE>
BSLS_KEYWORD_INLINE_VARIABLE constexpr bool is_member_function_pointer_v =
                                     is_member_function_pointer<t_TYPE>::value;
#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 ----------------------------------
 
/** @} */
/** @} */
/** @} */