boost/type_erasure/operators.hpp
// Boost.TypeErasure library
//
// Copyright 2011 Steven Watanabe
//
// 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)
//
// $Id: operators.hpp 83251 2013-03-02 19:23:44Z steven_watanabe $
#ifndef BOOST_TYPE_ERASURE_OPERATORS_HPP_INCLUDED
#define BOOST_TYPE_ERASURE_OPERATORS_HPP_INCLUDED
#include <iosfwd>
#include <boost/utility/enable_if.hpp>
#include <boost/type_erasure/detail/const.hpp>
#include <boost/type_erasure/call.hpp>
#include <boost/type_erasure/concept_interface.hpp>
#include <boost/type_erasure/placeholder.hpp>
#include <boost/type_erasure/concept_of.hpp>
#include <boost/type_erasure/derived.hpp>
#include <boost/type_erasure/rebind_any.hpp>
#include <boost/type_erasure/param.hpp>
#include <boost/type_erasure/check_match.hpp>
#include <boost/type_erasure/relaxed.hpp>
#include <boost/type_erasure/typeid_of.hpp>
namespace boost {
namespace type_erasure {
template<class Concept, class Placeholder>
class any;
/** INTERNAL ONLY */
#define BOOST_TYPE_ERASURE_UNARY_INPLACE_OPERATOR(name, op) \
template<class T = _self> \
struct name \
{ \
static void apply(T& arg) { op arg; } \
}; \
\
template<class T, class Base> \
struct concept_interface<name<T>, Base, T, \
typename ::boost::enable_if< \
detail::should_be_non_const<T, Base> \
>::type \
> : Base \
{ \
typedef typename ::boost::type_erasure::derived<Base>::type _derived; \
_derived& operator op() \
{ \
::boost::type_erasure::call(name<T>(), *this); \
return static_cast<_derived&>(*this); \
} \
typename ::boost::type_erasure::rebind_any<Base, T>::type operator op(int) \
{ \
typename ::boost::type_erasure::rebind_any<Base, T>::type result( \
static_cast<_derived&>(*this)); \
::boost::type_erasure::call(name<T>(), *this); \
return result; \
} \
}; \
\
template<class T, class Base> \
struct concept_interface<name<T>, Base, T, \
typename ::boost::enable_if< \
detail::should_be_const<T, Base> \
>::type \
> : Base \
{ \
typedef typename ::boost::type_erasure::derived<Base>::type _derived; \
const _derived& operator op() const \
{ \
::boost::type_erasure::call(name<T>(), *this); \
return static_cast<const _derived&>(*this); \
} \
typename ::boost::type_erasure::rebind_any<Base, T>::type operator op(int) const \
{ \
typename ::boost::type_erasure::rebind_any<Base, T>::type result( \
static_cast<const _derived&>(*this)); \
::boost::type_erasure::call(name<T>(), *this); \
return result; \
} \
};
/**
* The @ref incrementable concept allow pre and
* post increment on an @ref any. The contained
* type must provide a pre-increment operator.
*/
BOOST_TYPE_ERASURE_UNARY_INPLACE_OPERATOR(incrementable, ++)
/**
* The @ref decrementable concept allow pre and
* post decrement on an @ref any. The contained
* type must provide a pre-decrement operator.
*/
BOOST_TYPE_ERASURE_UNARY_INPLACE_OPERATOR(decrementable, --)
#undef BOOST_TYPE_ERASURE_UNARY_INPLACE_OPERATOR
/** INTERNAL ONLY */
#define BOOST_TYPE_ERASURE_UNARY_OPERATOR(name, op) \
template<class T = _self, class R = T> \
struct name \
{ \
static R apply(const T& arg) { return op arg; } \
}; \
\
template<class T, class R, class Base> \
struct concept_interface<name<T, R>, Base, T> : Base \
{ \
typename ::boost::type_erasure::rebind_any<Base, R>::type operator op() const \
{ \
return ::boost::type_erasure::call(name<T, R>(), *this); \
} \
};
/**
* The @ref complementable concept allow use of the bitwise
* complement operator on an @ref any.
*/
BOOST_TYPE_ERASURE_UNARY_OPERATOR(complementable, ~)
/**
* The @ref negatable concept allow use of the unary
* minus operator on an @ref any.
*/
BOOST_TYPE_ERASURE_UNARY_OPERATOR(negatable, -)
#undef BOOST_TYPE_ERASURE_UNARY_OPERATOR
template<class R, class T = _self>
struct dereferenceable
{
static R apply(const T& arg) { return *arg; }
};
/// \cond show_operators
template<class R, class T, class Base>
struct concept_interface<dereferenceable<R, T>, Base, T> : Base
{
typename ::boost::type_erasure::rebind_any<Base, R>::type operator*() const
{
return ::boost::type_erasure::call(dereferenceable<R, T>(), *this);
}
};
/// \endcond
/** INTERNAL ONLY */
#define BOOST_TYPE_ERASURE_BINARY_OPERATOR(name, op) \
template<class T = _self, class U = T, class R = T> \
struct name \
{ \
static R apply(const T& lhs, const U& rhs) { return lhs op rhs; } \
}; \
\
template<class T, class U, class R, class Base> \
struct concept_interface<name<T, U, R>, Base, T> : Base \
{ \
friend typename rebind_any<Base, R>::type \
operator op(const typename derived<Base>::type& lhs, \
typename as_param<Base, const U&>::type rhs) \
{ \
return ::boost::type_erasure::call(name<T, U, R>(), lhs, rhs); \
} \
}; \
\
template<class T, class U, class R, class Base> \
struct concept_interface< \
name<T, U, R>, \
Base, \
U, \
typename ::boost::disable_if< \
::boost::type_erasure::is_placeholder<T> >::type \
> : Base \
{ \
friend typename rebind_any<Base, R>::type \
operator op(const T& lhs, \
const typename derived<Base>::type& rhs) \
{ \
return ::boost::type_erasure::call(name<T, U, R>(), lhs, rhs); \
} \
};
BOOST_TYPE_ERASURE_BINARY_OPERATOR(addable, +)
BOOST_TYPE_ERASURE_BINARY_OPERATOR(subtractable, -)
BOOST_TYPE_ERASURE_BINARY_OPERATOR(multipliable, *)
BOOST_TYPE_ERASURE_BINARY_OPERATOR(dividable, /)
BOOST_TYPE_ERASURE_BINARY_OPERATOR(modable, %)
BOOST_TYPE_ERASURE_BINARY_OPERATOR(left_shiftable, <<)
BOOST_TYPE_ERASURE_BINARY_OPERATOR(right_shiftable, >>)
BOOST_TYPE_ERASURE_BINARY_OPERATOR(bitandable, &)
BOOST_TYPE_ERASURE_BINARY_OPERATOR(bitorable, |)
BOOST_TYPE_ERASURE_BINARY_OPERATOR(bitxorable, ^)
#undef BOOST_TYPE_ERASURE_BINARY_OPERATOR
/** INTERNAL ONLY */
#define BOOST_TYPE_ERASURE_ASSIGNMENT_OPERATOR(name, op) \
template<class T = _self, class U = T> \
struct name \
{ \
static void apply(T& lhs, const U& rhs) { lhs op rhs; } \
}; \
\
template<class T, class U, class Base> \
struct concept_interface<name<T, U>, Base, T, \
typename ::boost::disable_if< \
::boost::is_same< \
typename ::boost::type_erasure::placeholder_of<Base>::type, \
const T& \
> \
>::type \
> : Base \
{ \
friend typename detail::non_const_this_param<Base>::type& \
operator op(typename detail::non_const_this_param<Base>::type& lhs, \
typename as_param<Base, const U&>::type rhs) \
{ \
::boost::type_erasure::call(name<T, U>(),lhs, rhs); \
return lhs; \
} \
}; \
\
template<class T, class U, class Base> \
struct concept_interface< \
name<T, U>, \
Base, \
U, \
typename ::boost::disable_if< \
::boost::type_erasure::is_placeholder<T> >::type \
> : Base \
{ \
friend T& \
operator op(T& lhs, const typename derived<Base>::type& rhs) \
{ \
::boost::type_erasure::call(name<T, U>(),lhs, rhs); \
return lhs; \
} \
};
BOOST_TYPE_ERASURE_ASSIGNMENT_OPERATOR(add_assignable, +=)
BOOST_TYPE_ERASURE_ASSIGNMENT_OPERATOR(subtract_assignable, -=)
BOOST_TYPE_ERASURE_ASSIGNMENT_OPERATOR(multiply_assignable, *=)
BOOST_TYPE_ERASURE_ASSIGNMENT_OPERATOR(divide_assignable, /=)
BOOST_TYPE_ERASURE_ASSIGNMENT_OPERATOR(mod_assignable, %=)
BOOST_TYPE_ERASURE_ASSIGNMENT_OPERATOR(left_shift_assignable, <<=)
BOOST_TYPE_ERASURE_ASSIGNMENT_OPERATOR(right_shift_assignable, >>=)
BOOST_TYPE_ERASURE_ASSIGNMENT_OPERATOR(bitand_assignable, &=)
BOOST_TYPE_ERASURE_ASSIGNMENT_OPERATOR(bitor_assignable, |=)
BOOST_TYPE_ERASURE_ASSIGNMENT_OPERATOR(bitxor_assignable, ^=)
#undef BOOST_TYPE_ERASURE_ASSIGNMENT_OPERATOR
template<class T = _self, class U = T>
struct equality_comparable
{
static bool apply(const T& lhs, const U& rhs) { return lhs == rhs; }
};
/// \cond show_operators
template<class T, class U, class Base>
struct concept_interface<equality_comparable<T, U>, Base, T> : Base
{
friend bool operator==(const typename derived<Base>::type& lhs,
typename as_param<Base, const U&>::type rhs)
{
if(::boost::type_erasure::check_match(equality_comparable<T, U>(), lhs, rhs)) {
return ::boost::type_erasure::unchecked_call(equality_comparable<T, U>(), lhs, rhs);
} else {
return false;
}
}
friend bool operator!=(const typename derived<Base>::type& lhs,
typename as_param<Base, const U&>::type rhs)
{
return !(lhs == rhs);
}
};
template<class T, class U, class Base>
struct concept_interface<
equality_comparable<T, U>,
Base,
U,
typename ::boost::disable_if< ::boost::type_erasure::is_placeholder<T> >::type
> : Base
{
friend bool operator==(const T& lhs, const typename derived<Base>::type& rhs)
{
return ::boost::type_erasure::call(equality_comparable<T, U>(), lhs, rhs);
}
friend bool operator!=(const T& lhs, const typename derived<Base>::type& rhs)
{
return !(lhs == rhs);
}
};
/// \endcond
template<class T = _self, class U = T>
struct less_than_comparable
{
static bool apply(const T& lhs, const U& rhs) { return lhs < rhs; }
};
namespace detail {
template<class F, class T, class U>
bool less_impl(const F& f, const T& lhs, const U& rhs, ::boost::mpl::true_)
{
if(::boost::type_erasure::check_match(f, lhs, rhs)) {
return ::boost::type_erasure::unchecked_call(f, lhs, rhs);
} else {
return ::boost::type_erasure::typeid_of(
static_cast<const typename derived<T>::type&>(lhs)
).before(
::boost::type_erasure::typeid_of(
static_cast<const typename derived<U>::type&>(rhs)
)
) != false;
}
}
template<class F, class T, class U>
bool less_impl(const F& f, const T& lhs, const U& rhs, ::boost::mpl::false_)
{
return ::boost::type_erasure::call(f, lhs, rhs);
}
}
/// \cond show_operators
template<class T, class Base>
struct concept_interface<less_than_comparable<T, T>, Base, T> : Base
{
friend bool operator<(const typename derived<Base>::type& lhs,
typename as_param<Base, const T&>::type rhs)
{
return ::boost::type_erasure::detail::less_impl(
less_than_comparable<T, T>(),
lhs, rhs,
::boost::type_erasure::is_relaxed<
typename ::boost::type_erasure::concept_of<Base>::type>());
}
friend bool operator>=(const typename derived<Base>::type& lhs,
typename as_param<Base, const T&>::type rhs)
{
return !(lhs < rhs);
}
friend bool operator>(typename as_param<Base, const T&>::type lhs,
const typename derived<Base>::type& rhs)
{
return rhs < lhs;
}
friend bool operator<=(typename as_param<Base, const T&>::type lhs,
const typename derived<Base>::type& rhs)
{
return !(rhs < lhs);
}
};
template<class T, class U, class Base>
struct concept_interface<less_than_comparable<T, U>, Base, T> : Base
{
friend bool operator<(const typename derived<Base>::type& lhs,
typename as_param<Base, const U&>::type rhs)
{
return ::boost::type_erasure::call(less_than_comparable<T, U>(), lhs, rhs);
}
friend bool operator>=(const typename derived<Base>::type& lhs,
typename as_param<Base, const U&>::type rhs)
{
return !(lhs < rhs);
}
friend bool operator>(typename as_param<Base, const U&>::type lhs,
const typename derived<Base>::type& rhs)
{
return rhs < lhs;
}
friend bool operator<=(typename as_param<Base, const U&>::type lhs,
const typename derived<Base>::type& rhs)
{
return !(rhs < lhs);
}
};
template<class T, class U, class Base>
struct concept_interface<
less_than_comparable<T, U>,
Base,
U,
typename ::boost::disable_if< ::boost::type_erasure::is_placeholder<T> >::type
> : Base
{
friend bool operator<(const T& lhs, const typename derived<Base>::type& rhs)
{
return ::boost::type_erasure::call(less_than_comparable<T, U>(), lhs, rhs);
}
friend bool operator>=(const T& lhs, const typename derived<Base>::type& rhs)
{
return !(lhs < rhs);
}
friend bool operator>(const typename derived<Base>::type& lhs, const T& rhs)
{
return rhs < lhs;
}
friend bool operator<=(const typename derived<Base>::type& lhs, const T& rhs)
{
return !(rhs < lhs);
}
};
/// \endcond
template<class R, class T = _self, class N = std::ptrdiff_t>
struct subscriptable
{
static R apply(T& arg, const N& index) { return arg[index]; }
};
/// \cond show_operators
template<class R, class T, class N, class Base>
struct concept_interface<subscriptable<R, T, N>, Base, typename ::boost::remove_const<T>::type,
typename ::boost::enable_if<
::boost::type_erasure::detail::should_be_non_const<T, Base>
>::type
> : Base
{
typename ::boost::type_erasure::rebind_any<Base, R>::type operator[](
typename ::boost::type_erasure::as_param<Base, const N&>::type index)
{
return ::boost::type_erasure::call(subscriptable<R, T, N>(), *this, index);
}
};
template<class R, class T, class N, class Base>
struct concept_interface<subscriptable<R, T, N>, Base, typename ::boost::remove_const<T>::type,
typename ::boost::enable_if<
::boost::type_erasure::detail::should_be_const<T, Base>
>::type
> : Base
{
typename ::boost::type_erasure::rebind_any<Base, R>::type operator[](
typename ::boost::type_erasure::as_param<Base, const N&>::type index) const
{
return ::boost::type_erasure::call(subscriptable<R, const T, N>(), *this, index);
}
};
/// \endcond
/**
* The @ref ostreamable concept allows an @ref any to be
* written to a @c std::ostream.
*/
template<class Os = std::ostream, class T = _self>
struct ostreamable
{
static void apply(Os& out, const T& arg) { out << arg; }
};
/// \cond show_operators
template<class Base, class Os, class T>
struct concept_interface<ostreamable<Os, T>, Base, Os> : Base
{
friend typename detail::non_const_this_param<Base>::type&
operator<<(typename detail::non_const_this_param<Base>::type& lhs,
typename ::boost::type_erasure::as_param<Base, const T&>::type rhs)
{
::boost::type_erasure::call(ostreamable<Os, T>(), lhs, rhs);
return lhs;
}
};
template<class Base, class Os, class T>
struct concept_interface<
ostreamable<Os, T>,
Base,
T,
typename ::boost::disable_if< ::boost::type_erasure::is_placeholder<Os> >::type
> : Base
{
friend Os&
operator<<(Os& lhs,
const typename ::boost::type_erasure::derived<Base>::type& rhs)
{
::boost::type_erasure::call(ostreamable<Os, T>(), lhs, rhs);
return lhs;
}
};
/// \endcond
/**
* The @ref istreamable concept allows an @ref any to be
* read from a @c std::istream.
*/
template<class Is = std::istream, class T = _self>
struct istreamable
{
static void apply(Is& out, T& arg) { out >> arg; }
};
/// \cond show_operators
template<class Base, class Is, class T>
struct concept_interface<istreamable<Is, T>, Base, Is> : Base
{
friend typename detail::non_const_this_param<Base>::type&
operator>>(typename detail::non_const_this_param<Base>::type& lhs,
typename ::boost::type_erasure::as_param<Base, T&>::type rhs)
{
::boost::type_erasure::call(istreamable<Is, T>(), lhs, rhs);
return lhs;
}
};
template<class Base, class Is, class T>
struct concept_interface<
istreamable<Is, T>,
Base,
T,
typename ::boost::disable_if< ::boost::type_erasure::is_placeholder<Is> >::type
> : Base
{
friend Is&
operator>>(Is& lhs,
typename ::boost::type_erasure::derived<Base>::type& rhs)
{
::boost::type_erasure::call(istreamable<Is, T>(), lhs, rhs);
return lhs;
}
};
/// \endcond
}
}
#endif