bslmf_memberpointertraits.h

Go to the documentation of this file.

/// @file bslmf_memberpointertraits.h
///
/// The content of this file has been pre-processed for Doxygen.
///
 
 
// bslmf_memberpointertraits.h                                        -*-C++-*-
#ifndef INCLUDED_BSLMF_MEMBERPOINTERTRAITS
#define INCLUDED_BSLMF_MEMBERPOINTERTRAITS
 
#include <bsls_ident.h>
BSLS_IDENT("$Id: $")
 
/// @defgroup bslmf_memberpointertraits bslmf_memberpointertraits
/// @brief  Provide meta-function to detect pointer to member traits.
/// @addtogroup bsl
/// @{
/// @addtogroup bslmf
/// @{
/// @addtogroup bslmf_memberpointertraits
/// @{
///
/// <h1> Outline </h1>
/// * <a href="#bslmf_memberpointertraits-purpose"> Purpose</a>
/// * <a href="#bslmf_memberpointertraits-classes"> Classes </a>
/// * <a href="#bslmf_memberpointertraits-description"> Description </a>
///   * <a href="#bslmf_memberpointertraits-usage"> Usage </a>
///
/// # Purpose {#bslmf_memberpointertraits-purpose}
/// Provide meta-function to detect pointer to member traits.
///
/// # Classes {#bslmf_memberpointertraits-classes}
///
/// -  bslmf::MemberPointerTraits: meta-function to get member pointer traits
///
/// @see  bslmf_memberfunctionpointertraits
///
/// # Description {#bslmf_memberpointertraits-description}
/// This component provides a meta-function,
/// `bslmf::MemberPointerTraits`, that determines traits of a pointer-to-member
/// type, including the type of the object that it is a member of, and the type
/// of the member it addresses.
///
/// ## Usage {#bslmf_memberpointertraits-usage}
///
///
/// Define the following `struct` with the following members:
/// @code
/// struct MyTestClass {
///     int func1(int) { return 0; }
///     int d_int;
/// };
/// @endcode
/// In order to deduce the types of `func1` and `d_int`, we will use
/// `bslmf::MemberPointerTraits`.
/// @code
/// template <class MEMBER, class CLASS, class t_TYPE>
/// void checkMemberPointer(t_TYPE pointer)
/// {
///     (void) pointer;
///     typedef typename bslmf::MemberPointerTraits<t_TYPE>::MemberType
///         MemberType;
///     typedef typename bslmf::MemberPointerTraits<t_TYPE>::ClassType
///         ClassType;
///     assert(1 == (bsl::is_same<MemberType, MEMBER>::value));
///     assert(1 == (bsl::is_same<ClassType, CLASS>::value));
/// }
/// @endcode
/// The following program should compile and run without errors:
/// @code
/// void usageExample()
/// {
///     checkMemberPointer<int(int), MyTestClass>(&MyTestClass::func1);
///     checkMemberPointer<int, MyTestClass>(&MyTestClass::d_int);
/// }
/// @endcode
/// @}
/** @} */
/** @} */
 
/** @addtogroup bsl
 * @{
 */
/** @addtogroup bslmf
 * @{
 */
/** @addtogroup bslmf_memberpointertraits
 * @{
 */
 
#include <bslscm_version.h>
 
#include <bslmf_removecv.h>
 
 
namespace bslmf {
 
template <class t_TYPE>
struct MemberPointerTraits_Imp;
 
                         // =========================
                         // class MemberPointerTraits
                         // =========================
 
/// This utility `struct` template provides the following nested typedefs:
///: `ClassType`:  The type of the class for which the specified `t_TYPE` is
///:               a pointer to member object.
///: `MemberType`: The type of the member object of the class for which the
///:               specified `t_TYPE` is a pointer to member object.
/// These typedefs will only be defined if `t_TYPE` is a
template <class t_TYPE>
struct MemberPointerTraits
: public MemberPointerTraits_Imp<typename bsl::remove_cv<t_TYPE>::type> {
 
    // pointer-to-member-object type.  The primary (unspecialized)
    // MemberPointerTraits_Imp template is defined and empty.
};
 
                       // =============================
                       // class MemberPointerTraits_Imp
                       // =============================
 
/// Empty
///
/// See @ref bslmf_memberpointertraits 
template <class t_TYPE>
struct MemberPointerTraits_Imp {
};
 
template <class t_MEMBER_TYPE, class t_CLASS_TYPE>
struct MemberPointerTraits_Imp<t_MEMBER_TYPE t_CLASS_TYPE::*> {
    // TYPES
 
    /// `ClassType` is an alias to the type of the class for which the
    /// specified `t_TYPE` is a pointer to member object.
    typedef t_CLASS_TYPE ClassType;
 
    /// `MemberType` is an alias to the type of object to which the member
    /// object points.
    typedef t_MEMBER_TYPE MemberType;
};
 
}  // close package namespace
 
 
#endif  // INCLUDED_BSLMF_MEMBERPOINTERTRAITS
 
// ----------------------------------------------------------------------------
// Copyright 2022 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 ----------------------------------
 
/** @} */
/** @} */
/** @} */