stlx.h

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// Copyright 2014 GSI, Inc. All rights reserved.
//
// STL extensions
//
#ifndef _DDS_STLX_H_
#define _DDS_STLX_H_

namespace dds::misc
{
    namespace stlx
    {
        template <typename _T>
        struct remove_cref
        {
            typedef _T type;
        };

        template <typename _T>
        struct remove_cref<const _T&>
        {
            typedef _T type;
        };

        template <typename _Result, typename _Class, typename _Argument>
        class mem_fun1_t : public std::binary_function<_Class*,
                                                       typename remove_cref<_Argument>::type, // was: Argument
                                                       _Result>
        {
          public:
            explicit mem_fun1_t(_Result (_Class::*member)(_Argument))
                : member_(member)
            {
            }

            _Result operator()(_Class* object, _Argument argument) const
            {
                return (object->*member_)(argument);
            }

          private:
            _Result (_Class::*member_)(_Argument);
        };
        template <typename _Result, typename _Class, typename _Argument>
        mem_fun1_t<_Result, _Class, _Argument> mem_fun(_Result (_Class::*member)(_Argument))
        {
            return mem_fun1_t<_Result, _Class, _Argument>(member);
        }
        /*
         *
         * @brief The select1st function object takes a single argument, a pair, and returns the pair's first element.
         *
         */
        template <class _Pair>
        struct select1st : public std::unary_function<_Pair, typename _Pair::first_type>
        {
            typename _Pair::first_type& operator()(_Pair& __x) const
            {
                return __x.first;
            }
            const typename _Pair::first_type& operator()(const _Pair& __x) const
            {
                return __x.first;
            }
        };
        template <class _Pair>
        struct select2nd : public std::unary_function<_Pair, typename _Pair::second_type>
        {
            typename _Pair::second_type& operator()(_Pair& __x) const
            {
                return __x.second;
            }
            const typename _Pair::second_type& operator()(const _Pair& __x) const
            {
                return __x.second;
            }
        };
    }; // namespace stlx
};     // namespace dds::misc
#endif /*_DDS_STLX_H_*/