boost/icl/functors.hpp
/*-----------------------------------------------------------------------------+
Copyright (c) 2007-2009: Joachim Faulhaber
+------------------------------------------------------------------------------+
Distributed under the Boost Software License, Version 1.0.
(See accompanying file LICENCE.txt or copy at
http://www.boost.org/LICENSE_1_0.txt)
+-----------------------------------------------------------------------------*/
#ifndef BOOST_ICL_FUNCTORS_HPP_JOFA_080315
#define BOOST_ICL_FUNCTORS_HPP_JOFA_080315
#include <boost/type_traits.hpp>
#include <boost/mpl/if.hpp>
#include <boost/icl/type_traits/identity_element.hpp>
#include <boost/icl/type_traits/unit_element.hpp>
#include <boost/icl/type_traits/is_set.hpp>
#include <boost/icl/type_traits/has_set_semantics.hpp>
namespace boost{namespace icl
{
// ------------------------------------------------------------------------
template <typename Type> struct identity_based_inplace_combine
{
typedef Type& first_argument_type;
typedef const Type& second_argument_type;
typedef void result_type;
inline static Type identity_element() { return boost::icl::identity_element<Type>::value(); }
};
// ------------------------------------------------------------------------
template <typename Type> struct unit_element_based_inplace_combine
{
typedef Type& first_argument_type;
typedef const Type& second_argument_type;
typedef void result_type;
inline static Type identity_element() { return boost::icl::unit_element<Type>::value(); }
};
// ------------------------------------------------------------------------
template <typename Type> struct inplace_identity
: public identity_based_inplace_combine<Type>
{
typedef inplace_identity<Type> type;
void operator()(Type&, const Type&)const{}
};
template<>
inline std::string unary_template_to_string<inplace_identity>::apply()
{ return "i="; }
// ------------------------------------------------------------------------
template <typename Type> struct inplace_erasure
: public identity_based_inplace_combine<Type>
{
typedef inplace_erasure<Type> type;
typedef identity_based_inplace_combine<Type> base_type;
void operator()(Type& object, const Type& operand)const
{
if(object == operand)
//identity_element(); //JODO Old gcc-3.4.4 does not compile this
object = base_type::identity_element(); //<-- but this.
}
};
template<>
inline std::string unary_template_to_string<inplace_erasure>::apply()
{ return "0="; }
// ------------------------------------------------------------------------
template <typename Type> struct inplace_plus
: public identity_based_inplace_combine<Type>
{
typedef inplace_plus<Type> type;
void operator()(Type& object, const Type& operand)const
{ object += operand; }
static void version(Type&){}
};
template<>
inline std::string unary_template_to_string<inplace_plus>::apply() { return "+="; }
// ------------------------------------------------------------------------
template <typename Type> struct inplace_minus
: public identity_based_inplace_combine<Type>
{
typedef inplace_minus<Type> type;
void operator()(Type& object, const Type& operand)const
{ object -= operand; }
};
template<>
inline std::string unary_template_to_string<inplace_minus>::apply() { return "-="; }
// ------------------------------------------------------------------------
template <typename Type> struct inplace_bit_add
: public identity_based_inplace_combine<Type>
{
typedef inplace_bit_add<Type> type;
void operator()(Type& object, const Type& operand)const
{ object |= operand; }
static void version(Type&){}
};
template<>
inline std::string unary_template_to_string<inplace_bit_add>::apply() { return "b|="; }
// ------------------------------------------------------------------------
template <typename Type> struct inplace_bit_subtract
: public identity_based_inplace_combine<Type>
{
typedef inplace_bit_subtract<Type> type;
void operator()(Type& object, const Type& operand)const
{ object &= ~operand; }
};
template<>
inline std::string unary_template_to_string<inplace_bit_subtract>::apply() { return "b-="; }
// ------------------------------------------------------------------------
template <typename Type> struct inplace_bit_and
: public identity_based_inplace_combine<Type>
{
typedef inplace_bit_and<Type> type;
void operator()(Type& object, const Type& operand)const
{ object &= operand; }
};
template<>
inline std::string unary_template_to_string<inplace_bit_and>::apply() { return "b&="; }
// ------------------------------------------------------------------------
template <typename Type> struct inplace_bit_xor
: public identity_based_inplace_combine<Type>
{
typedef inplace_bit_xor<Type> type;
void operator()(Type& object, const Type& operand)const
{ object ^= operand; }
};
// ------------------------------------------------------------------------
template <typename Type> struct inplace_et
: public identity_based_inplace_combine<Type>
{
typedef inplace_et<Type> type;
void operator()(Type& object, const Type& operand)const
{ object &= operand; }
};
template<>
inline std::string unary_template_to_string<inplace_et>::apply() { return "&="; }
// ------------------------------------------------------------------------
template <typename Type> struct inplace_caret
: public identity_based_inplace_combine<Type>
{
typedef inplace_caret<Type> type;
void operator()(Type& object, const Type& operand)const
{ object ^= operand; }
};
template<>
inline std::string unary_template_to_string<inplace_caret>::apply() { return "^="; }
// ------------------------------------------------------------------------
template <typename Type> struct inplace_insert
: public identity_based_inplace_combine<Type>
{
typedef inplace_insert<Type> type;
void operator()(Type& object, const Type& operand)const
{ insert(object,operand); }
};
template<>
inline std::string unary_template_to_string<inplace_insert>::apply() { return "ins="; }
// ------------------------------------------------------------------------
template <typename Type> struct inplace_erase
: public identity_based_inplace_combine<Type>
{
typedef inplace_erase<Type> type;
void operator()(Type& object, const Type& operand)const
{ erase(object,operand); }
};
template<>
inline std::string unary_template_to_string<inplace_erase>::apply() { return "ers="; }
// ------------------------------------------------------------------------
template <typename Type> struct inplace_star
: public identity_based_inplace_combine<Type> //JODO unit_element_
{
typedef inplace_star<Type> type;
void operator()(Type& object, const Type& operand)const
{ object *= operand; }
};
template<>
inline std::string unary_template_to_string<inplace_star>::apply() { return "*="; }
// ------------------------------------------------------------------------
template <typename Type> struct inplace_slash
: public identity_based_inplace_combine<Type> //JODO unit_element_
{
typedef inplace_slash<Type> type;
void operator()(Type& object, const Type& operand)const
{ object /= operand; }
};
template<>
inline std::string unary_template_to_string<inplace_slash>::apply() { return "/="; }
// ------------------------------------------------------------------------
template <typename Type> struct inplace_max
: public identity_based_inplace_combine<Type>
{
typedef inplace_max<Type> type;
void operator()(Type& object, const Type& operand)const
{
if(object < operand)
object = operand;
}
};
template<>
inline std::string unary_template_to_string<inplace_max>::apply() { return "max="; }
// ------------------------------------------------------------------------
template <typename Type> struct inplace_min
: public identity_based_inplace_combine<Type>
{
typedef inplace_min<Type> type;
void operator()(Type& object, const Type& operand)const
{
if(object > operand)
object = operand;
}
};
template<>
inline std::string unary_template_to_string<inplace_min>::apply() { return "min="; }
//--------------------------------------------------------------------------
// Inter_section functor
//--------------------------------------------------------------------------
template<class Type> struct inter_section
: public identity_based_inplace_combine<Type>
{
typedef typename boost::mpl::
if_<has_set_semantics<Type>,
icl::inplace_et<Type>,
icl::inplace_plus<Type>
>::type
type;
void operator()(Type& object, const Type& operand)const
{
type()(object, operand);
}
};
//--------------------------------------------------------------------------
// Inverse functor
//--------------------------------------------------------------------------
template<class Functor> struct inverse;
template<class Type>
struct inverse<icl::inplace_plus<Type> >
{ typedef icl::inplace_minus<Type> type; };
template<class Type>
struct inverse<icl::inplace_minus<Type> >
{ typedef icl::inplace_plus<Type> type; };
template<class Type>
struct inverse<icl::inplace_bit_add<Type> >
{ typedef icl::inplace_bit_subtract<Type> type; };
template<class Type>
struct inverse<icl::inplace_bit_subtract<Type> >
{ typedef icl::inplace_bit_add<Type> type; };
template<class Type>
struct inverse<icl::inplace_et<Type> >
{ typedef icl::inplace_caret<Type> type; };
template<class Type>
struct inverse<icl::inplace_caret<Type> >
{ typedef icl::inplace_et<Type> type; };
template<class Type>
struct inverse<icl::inplace_bit_and<Type> >
{ typedef icl::inplace_bit_xor<Type> type; };
template<class Type>
struct inverse<icl::inplace_bit_xor<Type> >
{ typedef icl::inplace_bit_and<Type> type; };
template<class Type>
struct inverse<icl::inplace_star<Type> >
{ typedef icl::inplace_slash<Type> type; };
template<class Type>
struct inverse<icl::inplace_slash<Type> >
{ typedef icl::inplace_star<Type> type; };
template<class Type>
struct inverse<icl::inplace_max<Type> >
{ typedef icl::inplace_min<Type> type; };
template<class Type>
struct inverse<icl::inplace_min<Type> >
{ typedef icl::inplace_max<Type> type; };
template<class Type>
struct inverse<icl::inplace_identity<Type> >
{ typedef icl::inplace_erasure<Type> type; };
// If a Functor
template<class Functor>
struct inverse
{
typedef typename
remove_reference<typename Functor::first_argument_type>::type argument_type;
typedef icl::inplace_erasure<argument_type> type;
};
//--------------------------------------------------------------------------
// Inverse inter_section functor
//--------------------------------------------------------------------------
template<class Type>
struct inverse<icl::inter_section<Type> >
: public identity_based_inplace_combine<Type>
{
typedef typename boost::mpl::
if_<has_set_semantics<Type>,
icl::inplace_caret<Type>,
icl::inplace_minus<Type>
>::type
type;
void operator()(Type& object, const Type& operand)const
{
type()(object, operand);
}
};
//--------------------------------------------------------------------------
// Positive or negative functor trait
//--------------------------------------------------------------------------
// A binary operation - is negative (or inverting) with respect to the
// neutral element iff it yields the inverse element if it is applied to the
// identity element:
// 0 - x = -x
// For a functor that wraps the inplace of op-assign version this is
// equivalent to
//
// T x = ..., y;
// y = Functor::identity_element();
// Functor()(y, x); // y == inverse_of(x)
template<class Functor> struct is_negative;
template<class Functor>
struct is_negative
{
typedef is_negative<Functor> type;
BOOST_STATIC_CONSTANT(bool, value = false);
};
template<class Type>
struct is_negative<icl::inplace_minus<Type> >
{
typedef is_negative type;
BOOST_STATIC_CONSTANT(bool, value = true);
};
template<class Type>
struct is_negative<icl::inplace_bit_subtract<Type> >
{
typedef is_negative type;
BOOST_STATIC_CONSTANT(bool, value = true);
};
//--------------------------------------------------------------------------
// Pro- or in-version functor
//--------------------------------------------------------------------------
template<class Combiner> struct conversion;
template<class Combiner>
struct conversion
{
typedef conversion<Combiner> type;
typedef typename
remove_const<
typename remove_reference<typename Combiner::first_argument_type
>::type
>::type
argument_type;
// The proversion of an op-assign functor o= lets the value unchanged
// (0 o= x) == x;
// Example += : (0 += x) == x
static argument_type proversion(const argument_type& value)
{
return value;
}
// The inversion of an op-assign functor o= inverts the value x
// to it's inverse element -x
// (0 o= x) == -x;
// Example -= : (0 -= x) == -x
static argument_type inversion(const argument_type& value)
{
argument_type inverse = Combiner::identity_element();
Combiner()(inverse, value);
return inverse;
}
};
template<class Combiner> struct version : public conversion<Combiner>
{
typedef version<Combiner> type;
typedef conversion<Combiner> base_type;
typedef typename base_type::argument_type argument_type;
argument_type operator()(const argument_type& value)
{ return base_type::proversion(value); }
};
template<>struct version<icl::inplace_minus<short > >{short operator()(short val){return -val;}};
template<>struct version<icl::inplace_minus<int > >{int operator()(int val){return -val;}};
template<>struct version<icl::inplace_minus<long > >{long operator()(long val){return -val;}};
template<>struct version<icl::inplace_minus<long long > >{long long operator()(long long val){return -val;}};
template<>struct version<icl::inplace_minus<float > >{float operator()(float val){return -val;}};
template<>struct version<icl::inplace_minus<double > >{double operator()(double val){return -val;}};
template<>struct version<icl::inplace_minus<long double> >{long double operator()(long double val){return -val;}};
template<class Type>
struct version<icl::inplace_minus<Type> > : public conversion<icl::inplace_minus<Type> >
{
typedef version<icl::inplace_minus<Type> > type;
typedef conversion<icl::inplace_minus<Type> > base_type;
typedef typename base_type::argument_type argument_type;
Type operator()(const Type& value)
{
return base_type::inversion(value);
}
};
}} // namespace icl boost
#endif
