operators.hpp

C++的一个好库。。。现在很流行

// Boost Lambda Library - operators.hpp --------------------------------------

// Copyright (C) 1999, 2000 Jaakko J鋜vi ([e-mail])
//
// Distributed under 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 www.boost.org

// ---------------------------------------------------------------

#ifndef BOOST_LAMBDA_OPERATORS_HPP
#define BOOST_LAMBDA_OPERATORS_HPP

#include "boost/lambda/detail/is_instance_of.hpp"

namespace boost { 
namespace lambda {

#if defined BOOST_LAMBDA_BE1
#error "Multiple defines of BOOST_LAMBDA_BE1"
#endif

  // For all BOOSTA_LAMBDA_BE* macros:

  // CONSTA must be either 'A' or 'const A'
  // CONSTB must be either 'B' or 'const B'

  // It is stupid to have the names A and B as macro arguments, but it avoids
  // the need to pass in emtpy macro arguments, which gives warnings on some
  // compilers

#define BOOST_LAMBDA_BE1(OPER_NAME, ACTION, CONSTA, CONSTB, CONVERSION)      \
template<class Arg, class B>                                                 \
inline const                                                                 \
lambda_functor<                                                              \
  lambda_functor_base<                                                       \
    ACTION,                                                                  \
    tuple<lambda_functor<Arg>, typename CONVERSION <CONSTB>::type>         \
  >                                                                          \
>                                                                            \
OPER_NAME (const lambda_functor<Arg>& a, CONSTB& b) {                      \
  return                                                                     \
    lambda_functor_base<                                                     \
      ACTION,                                                                \
      tuple<lambda_functor<Arg>, typename CONVERSION <CONSTB>::type>       \
    >                                                                        \
   (tuple<lambda_functor<Arg>, typename CONVERSION <CONSTB>::type>(a, b)); \
}


#if defined BOOST_LAMBDA_BE2
#error "Multiple defines of BOOST_LAMBDA_BE2"
#endif

#define BOOST_LAMBDA_BE2(OPER_NAME, ACTION, CONSTA, CONSTB, CONVERSION)      \
template<class A, class Arg>                                                 \
inline const                                                                 \
lambda_functor<                                                              \
  lambda_functor_base<                                                       \
    ACTION,                                                                  \
    tuple<typename CONVERSION <CONSTA>::type, lambda_functor<Arg> >        \
  >                                                                          \
>                                                                            \
OPER_NAME (CONSTA& a, const lambda_functor<Arg>& b) {                      \
  return                                                                     \
    lambda_functor_base<                                                     \
      ACTION,                                                                \
      tuple<typename CONVERSION <CONSTA>::type, lambda_functor<Arg> >      \
    >                                                                        \
  (tuple<typename CONVERSION <CONSTA>::type, lambda_functor<Arg> >(a, b)); \
}


#if defined BOOST_LAMBDA_BE3
#error "Multiple defines of BOOST_LAMBDA_BE3"
#endif

#define BOOST_LAMBDA_BE3(OPER_NAME, ACTION, CONSTA, CONSTB, CONVERSION)    \
template<class ArgA, class ArgB>                                           \
inline const                                                               \
lambda_functor<                                                            \
  lambda_functor_base<                                                     \
    ACTION,                                                                \
    tuple<lambda_functor<ArgA>, lambda_functor<ArgB> >                     \
  >                                                                        \
>                                                                          \
OPER_NAME (const lambda_functor<ArgA>& a, const lambda_functor<ArgB>& b) { \
  return                                                                   \
    lambda_functor_base<                                                   \
      ACTION,                                                              \
      tuple<lambda_functor<ArgA>, lambda_functor<ArgB> >                   \
    >                                                                      \
  (tuple<lambda_functor<ArgA>, lambda_functor<ArgB> >(a, b));              \
}

#if defined BOOST_LAMBDA_BE
#error "Multiple defines of BOOST_LAMBDA_BE"
#endif

#define BOOST_LAMBDA_BE(OPER_NAME, ACTION, CONSTA, CONSTB, CONST_CONVERSION) \
BOOST_LAMBDA_BE1(OPER_NAME, ACTION, CONSTA, CONSTB, CONST_CONVERSION)        \
BOOST_LAMBDA_BE2(OPER_NAME, ACTION, CONSTA, CONSTB, CONST_CONVERSION)        \
BOOST_LAMBDA_BE3(OPER_NAME, ACTION, CONSTA, CONSTB, CONST_CONVERSION)

#define BOOST_LAMBDA_EMPTY() 

BOOST_LAMBDA_BE(operator+, arithmetic_action<plus_action>, const A, const B, const_copy_argument)
BOOST_LAMBDA_BE(operator-, arithmetic_action<minus_action>, const A, const B, const_copy_argument)
BOOST_LAMBDA_BE(operator*, arithmetic_action<multiply_action>, const A, const B, const_copy_argument)
BOOST_LAMBDA_BE(operator/, arithmetic_action<divide_action>, const A, const B, const_copy_argument)
BOOST_LAMBDA_BE(operator%, arithmetic_action<remainder_action>, const A, const B, const_copy_argument)
BOOST_LAMBDA_BE(operator<<, bitwise_action<leftshift_action>, const A, const B, const_copy_argument)
BOOST_LAMBDA_BE(operator>>, bitwise_action<rightshift_action>, const A, const B, const_copy_argument)
BOOST_LAMBDA_BE(operator&, bitwise_action<and_action>, const A, const B, const_copy_argument)
BOOST_LAMBDA_BE(operator|, bitwise_action<or_action>, const A, const B, const_copy_argument)
BOOST_LAMBDA_BE(operator^, bitwise_action<xor_action>, const A, const B, const_copy_argument)
BOOST_LAMBDA_BE(operator&&, logical_action<and_action>, const A, const B, const_copy_argument)
BOOST_LAMBDA_BE(operator||, logical_action<or_action>, const A, const B, const_copy_argument)
BOOST_LAMBDA_BE(operator<, relational_action<less_action>, const A, const B, const_copy_argument)
BOOST_LAMBDA_BE(operator>, relational_action<greater_action>, const A, const B, const_copy_argument)
BOOST_LAMBDA_BE(operator<=, relational_action<lessorequal_action>, const A, const B, const_copy_argument)
BOOST_LAMBDA_BE(operator>=, relational_action<greaterorequal_action>, const A, const B, const_copy_argument)
BOOST_LAMBDA_BE(operator==, relational_action<equal_action>, const A, const B, const_copy_argument)
BOOST_LAMBDA_BE(operator!=, relational_action<notequal_action>, const A, const B, const_copy_argument)

BOOST_LAMBDA_BE(operator+=, arithmetic_assignment_action<plus_action>, A, const B, reference_argument)
BOOST_LAMBDA_BE(operator-=, arithmetic_assignment_action<minus_action>, A, const B, reference_argument)
BOOST_LAMBDA_BE(operator*=, arithmetic_assignment_action<multiply_action>, A, const B, reference_argument)
BOOST_LAMBDA_BE(operator/=, arithmetic_assignment_action<divide_action>, A, const B, reference_argument)
BOOST_LAMBDA_BE(operator%=, arithmetic_assignment_action<remainder_action>, A, const B, reference_argument)
BOOST_LAMBDA_BE(operator<<=, bitwise_assignment_action<leftshift_action>, A, const B, reference_argument)
BOOST_LAMBDA_BE(operator>>=, bitwise_assignment_action<rightshift_action>, A, const B, reference_argument)
BOOST_LAMBDA_BE(operator&=, bitwise_assignment_action<and_action>, A, const B, reference_argument)
BOOST_LAMBDA_BE(operator|=, bitwise_assignment_action<or_action>, A, const B, reference_argument)
BOOST_LAMBDA_BE(operator^=, bitwise_assignment_action<xor_action>, A, const B, reference_argument)


// A special trick for comma operator for correct preprocessing
#if defined BOOST_LAMBDA_COMMA_OPERATOR_NAME
#error "Multiple defines of BOOST_LAMBDA_COMMA_OPERATOR_NAME"
#endif

#define BOOST_LAMBDA_COMMA_OPERATOR_NAME operator,

BOOST_LAMBDA_BE1(BOOST_LAMBDA_COMMA_OPERATOR_NAME, other_action<comma_action>, const A, const B, const_copy_argument)
BOOST_LAMBDA_BE2(BOOST_LAMBDA_COMMA_OPERATOR_NAME, other_action<comma_action>, const A, const B, const_copy_argument)
BOOST_LAMBDA_BE3(BOOST_LAMBDA_COMMA_OPERATOR_NAME, other_action<comma_action>, const A, const B, const_copy_argument)



namespace detail {

// special cases for ostream& << Any and istream& >> Any ---------------
// the actual stream classes may vary and thus a specialisation for, 
// say ostream& does not match (the general case above is chosen). 
// Therefore we specialise for non-const reference:
// if the left argument is a stream, we store the stream as reference
// if it is something else, we store a const plain by default

// Note that the overloading is const vs. non-const first argument

#ifdef BOOST_NO_TEMPLATED_STREAMS
template<class T> struct convert_ostream_to_ref_others_to_c_plain_by_default {
  typedef typename detail::IF<
                       boost::is_convertible<T*, std::ostream*>::value,
                       T&,
                       typename const_copy_argument <T>::type
                     >::RET type;
};

template<class T> struct convert_istream_to_ref_others_to_c_plain_by_default {
  typedef typename detail::IF<
                       boost::is_convertible<T*, std::istream*>::value,
                       T&,
                       typename const_copy_argument <T>::type
                     >::RET type;
};
#else

template<class T> struct convert_ostream_to_ref_others_to_c_plain_by_default {
  typedef typename detail::IF<
                       is_instance_of_2<
                         T, std::basic_ostream
                       >::value,