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boost/assign/list_inserter.hpp

// Boost.Assign library
//
//  Copyright Thorsten Ottosen 2003-2004. Use, modification and
//  distribution is subject to the Boost Software License, Version
//  1.0. (See accompanying file LICENSE_1_0.txt or copy at
//  http://www.boost.org/LICENSE_1_0.txt)
//
// For more information, see http://www.boost.org/libs/assign/
//

#ifndef BOOST_ASSIGN_LIST_INSERTER_HPP
#define BOOST_ASSIGN_LIST_INSERTER_HPP

#if defined(_MSC_VER) && (_MSC_VER >= 1020)
# pragma once
#endif

#include <boost/detail/workaround.hpp>

#include <boost/mpl/if.hpp>
#include <boost/type_traits/is_same.hpp>
#include <boost/config.hpp>
#include <cstddef>

#include <boost/preprocessor/repetition/enum_binary_params.hpp>
#include <boost/preprocessor/repetition/enum_params.hpp>
#include <boost/preprocessor/cat.hpp>
#include <boost/preprocessor/iteration/local.hpp>
#include <boost/preprocessor/arithmetic/inc.hpp>

namespace boost
{
namespace assign_detail
{
    template< class T >
    struct repeater
    {
        std::size_t  sz;
        T            val;

        repeater( const repeater& r ) : sz( r.sz ), val( r.val )
        { }
        
        repeater( std::size_t sz, T r ) : sz( sz ), val( r )
        { }
    };
    
    template< class Fun >
    struct fun_repeater
    {
        std::size_t  sz;
        Fun          val;
        
        fun_repeater( const fun_repeater& r ) : sz( r.sz ), val( r.val )
        { }

        fun_repeater( std::size_t sz, Fun r ) : sz( sz ), val( r )
        { }
    };
    
    template< class C >
    class call_push_back
    {
        C& c_;
    public:
        call_push_back( const call_push_back& r ) : c_( r.c_ )
        { }

        call_push_back( C& c ) : c_( c )
        { }
        
        template< class T >
        void operator()( T r ) 
        {
            c_.push_back( r );
        }
    };
    
    template< class C >
    class call_push_front
    {
        C& c_;
    public:
        call_push_front( const call_push_front& r ) : c_( r.c_ )
        { }

        call_push_front( C& c ) : c_( c )
        { }
        
        template< class T >
        void operator()( T r ) 
        {
            c_.push_front( r );
        }
    };
    
    template< class C >
    class call_push
    {
        C& c_;
    public:
        call_push( const call_push& r ) : c_( r.c_ )
        { }
            
        call_push( C& c ) : c_( c )
        { }
    
        template< class T >
        void operator()( T r ) 
        {
            c_.push( r );
        }
    };
    
    template< class C >
    class call_insert
    {
        C& c_;
    public:
        call_insert( const call_insert& r ) : c_( r.c_ )
        { }

        call_insert( C& c ) : c_( c )
        { }
    
        template< class T >
        void operator()( T r ) 
        {
            c_.insert( r );
        }
    };

    struct forward_n_arguments {};
    
} // namespace 'assign_detail'

namespace assign
{

    template< class T >
    inline assign_detail::repeater<T>
    repeat( std::size_t sz, T r )
    {
        return assign_detail::repeater<T>( sz, r );
    }
    
    template< class Function >
    inline assign_detail::fun_repeater<Function>
    repeat_fun( std::size_t sz, Function r )
    {
        return assign_detail::fun_repeater<Function>( sz, r );
    }
    

    template< class Function, class Argument = assign_detail::forward_n_arguments > 
    class list_inserter
    {
        struct single_arg_type {};
        struct n_arg_type      {};

        typedef BOOST_DEDUCED_TYPENAME mpl::if_c< is_same<Argument,assign_detail::forward_n_arguments>::value,
                                                  n_arg_type,
                                                  single_arg_type >::type arg_type;  
            
    public:
        
        list_inserter( Function fun ) : insert_( fun )
        {}
        
        template< class Function2, class Arg >
        list_inserter( const list_inserter<Function2,Arg>& r ) 
        : insert_( r.fun_private() ) 
        {}

        list_inserter( const list_inserter& r ) : insert_( r.insert_ )
        {}

        list_inserter& operator()()
        {
            insert_( Argument() );
            return *this;
        }
        
        template< class T >
        list_inserter& operator=( T r )
        {
            insert_( r );
            return *this;
        }
        
        template< class T >
        list_inserter& operator=( assign_detail::repeater<T> r )
        {
            return operator,( r );
        }
        
        template< class Nullary_function >
        list_inserter& operator=( assign_detail::fun_repeater<Nullary_function> r )
        {
            //BOOST_STATIC_ASSERT( function_traits<Nullary_function>::arity == 0 );
            //BOOST_STATIC_ASSERT( is_convertible< BOOST_DEDUCED_TYPENAME function_traits<
            //                      Nullary_function>::result_type >,T>::value );

            return operator,( r );
        }
        
        template< class T >
        list_inserter& operator,( T r )
        {
            insert_( r  );
            return *this;
        }

        template< class T >
        list_inserter& operator,( assign_detail::repeater<T> r )
        {
            return repeat( r.sz, r.val ); 
        }
        
        template< class Nullary_function >
        list_inserter& operator,( assign_detail::fun_repeater<Nullary_function> r )
        {
            return repeat_fun( r.sz, r.val ); 
        }

        template< class T >
        list_inserter& repeat( std::size_t sz, T r )
        {
            std::size_t i = 0;
            while( i++ != sz )
                insert_( r );
            return *this;
        }
        
        template< class Nullary_function >
        list_inserter& repeat_fun( std::size_t sz, Nullary_function fun )
        {
            std::size_t i = 0;
            while( i++ != sz )
                insert_( fun() );
            return *this;
        }

        
#if BOOST_WORKAROUND(BOOST_MSVC, <= 1300)

        template< class T >
        list_inserter& operator()( const T& t )
#else        
        template< class T >
        list_inserter& operator()( T t )
#endif       
        {
            insert_( t );
            return *this;
        }

#ifndef BOOST_ASSIGN_MAX_PARAMS // use user's value
#define BOOST_ASSIGN_MAX_PARAMS 5        
#endif
#define BOOST_ASSIGN_MAX_PARAMETERS (BOOST_ASSIGN_MAX_PARAMS - 1)
#define BOOST_ASSIGN_PARAMS1(n) BOOST_PP_ENUM_PARAMS(n, class T)
#define BOOST_ASSIGN_PARAMS2(n) BOOST_PP_ENUM_BINARY_PARAMS(n, T, t)
#define BOOST_ASSIGN_PARAMS3(n) BOOST_PP_ENUM_PARAMS(n, t)
        
#define BOOST_PP_LOCAL_LIMITS (1, BOOST_ASSIGN_MAX_PARAMETERS)
#define BOOST_PP_LOCAL_MACRO(n) \
    template< class T, BOOST_ASSIGN_PARAMS1(n) > \
    list_inserter& operator()(T t, BOOST_ASSIGN_PARAMS2(n) ) \
        { \
            BOOST_PP_CAT(insert, BOOST_PP_INC(n))(t, BOOST_ASSIGN_PARAMS3(n), arg_type()); \
            return *this; \
        } \
        /**/

#include BOOST_PP_LOCAL_ITERATE()
        

#define BOOST_PP_LOCAL_LIMITS (1, BOOST_ASSIGN_MAX_PARAMETERS)
#define BOOST_PP_LOCAL_MACRO(n) \
    template< class T, BOOST_ASSIGN_PARAMS1(n) > \
    void BOOST_PP_CAT(insert, BOOST_PP_INC(n))(T t, BOOST_ASSIGN_PARAMS2(n), single_arg_type) \
    { \
        insert_( Argument(t, BOOST_ASSIGN_PARAMS3(n) )); \
    } \
    /**/
        
#include BOOST_PP_LOCAL_ITERATE()

#define BOOST_PP_LOCAL_LIMITS (1, BOOST_ASSIGN_MAX_PARAMETERS)
#define BOOST_PP_LOCAL_MACRO(n) \
    template< class T, BOOST_ASSIGN_PARAMS1(n) > \
    void BOOST_PP_CAT(insert, BOOST_PP_INC(n))(T t, BOOST_ASSIGN_PARAMS2(n), n_arg_type) \
    { \
        insert_(t, BOOST_ASSIGN_PARAMS3(n) ); \
    } \
    /**/
        
#include BOOST_PP_LOCAL_ITERATE()

        
        Function fun_private() const
        {
            return insert_;
        }

    private:
        
        list_inserter& operator=( const list_inserter& );
        Function insert_;
    };
    
    template< class Function >
    inline list_inserter< Function >
    make_list_inserter( Function fun )
    {
        return list_inserter< Function >( fun );
    }
    
    template< class Function, class Argument >
    inline list_inserter<Function,Argument>
    make_list_inserter( Function fun, Argument* )
    {
        return list_inserter<Function,Argument>( fun );
    }

    template< class C >
    inline list_inserter< assign_detail::call_push_back<C>, 
                          BOOST_DEDUCED_TYPENAME C::value_type >
    push_back( C& c )
    {
        static BOOST_DEDUCED_TYPENAME C::value_type* p = 0;
        return make_list_inserter( assign_detail::call_push_back<C>( c ), 
                                   p );
    }
    
    template< class C >
    inline list_inserter< assign_detail::call_push_front<C>,
                          BOOST_DEDUCED_TYPENAME C::value_type >
    push_front( C& c )
    {
        static BOOST_DEDUCED_TYPENAME C::value_type* p = 0;
        return make_list_inserter( assign_detail::call_push_front<C>( c ),
                                   p );
    }

    template< class C >
    inline list_inserter< assign_detail::call_insert<C>, 
                          BOOST_DEDUCED_TYPENAME C::value_type >
    insert( C& c )
    {
        static BOOST_DEDUCED_TYPENAME C::value_type* p = 0;
        return make_list_inserter( assign_detail::call_insert<C>( c ),
                                   p );
    }

    template< class C >
    inline list_inserter< assign_detail::call_push<C>, 
                          BOOST_DEDUCED_TYPENAME C::value_type >
    push( C& c )
    {
        static BOOST_DEDUCED_TYPENAME C::value_type* p = 0;
        return make_list_inserter( assign_detail::call_push<C>( c ),
                                   p );
    }
    
} // namespace 'assign'
} // namespace 'boost'

#undef BOOST_ASSIGN_PARAMS1
#undef BOOST_ASSIGN_PARAMS2
#undef BOOST_ASSIGN_PARAMS3
#undef BOOST_ASSIGN_MAX_PARAMETERS

#endif