boost/flyweight/flyweight.hpp
/* Flyweight class.
*
* Copyright 2006-2008 Joaquin M Lopez Munoz.
* 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)
*
* See http://www.boost.org/libs/flyweight for library home page.
*/
#ifndef BOOST_FLYWEIGHT_FLYWEIGHT_HPP
#define BOOST_FLYWEIGHT_FLYWEIGHT_HPP
#if defined(_MSC_VER)&&(_MSC_VER>=1200)
#pragma once
#endif
#include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */
#include <algorithm>
#include <boost/detail/workaround.hpp>
#include <boost/flyweight/detail/default_value_policy.hpp>
#include <boost/flyweight/detail/flyweight_core.hpp>
#include <boost/flyweight/factory_tag.hpp>
#include <boost/flyweight/flyweight_fwd.hpp>
#include <boost/flyweight/locking_tag.hpp>
#include <boost/flyweight/simple_locking_fwd.hpp>
#include <boost/flyweight/static_holder_fwd.hpp>
#include <boost/flyweight/hashed_factory_fwd.hpp>
#include <boost/flyweight/holder_tag.hpp>
#include <boost/flyweight/refcounted_fwd.hpp>
#include <boost/flyweight/tag.hpp>
#include <boost/flyweight/tracking_tag.hpp>
#include <boost/mpl/assert.hpp>
#include <boost/mpl/if.hpp>
#include <boost/mpl/not.hpp>
#include <boost/mpl/or.hpp>
#include <boost/parameter/binding.hpp>
#include <boost/preprocessor/repetition/enum_params.hpp>
#include <boost/type_traits/is_same.hpp>
#include <boost/utility/swap.hpp>
#if BOOST_WORKAROUND(BOOST_MSVC,BOOST_TESTED_AT(1400))
#pragma warning(push)
#pragma warning(disable:4521) /* multiple copy ctors */
#endif
namespace boost{
namespace flyweights{
namespace detail{
/* Used for the detection of unmatched template args in a
* flyweight instantiation.
*/
struct unmatched_arg;
/* Boost.Parameter structures for use in flyweight.
* NB: these types are derived from instead of typedef'd to force their
* instantiation, which solves http://bugs.sun.com/view_bug.do?bug_id=6782987
* as found out by Simon Atanasyan.
*/
struct flyweight_signature:
parameter::parameters<
parameter::optional<
parameter::deduced<tag<> >,
detail::is_tag<boost::mpl::_>
>,
parameter::optional<
parameter::deduced<tracking<> >,
is_tracking<boost::mpl::_>
>,
parameter::optional<
parameter::deduced<factory<> >,
is_factory<boost::mpl::_>
>,
parameter::optional<
parameter::deduced<locking<> >,
is_locking<boost::mpl::_>
>,
parameter::optional<
parameter::deduced<holder<> >,
is_holder<boost::mpl::_>
>
>
{};
struct flyweight_unmatched_signature:
parameter::parameters<
parameter::optional<
parameter::deduced<
detail::unmatched_arg
>,
mpl::not_<
mpl::or_<
detail::is_tag<boost::mpl::_>,
is_tracking<boost::mpl::_>,
is_factory<boost::mpl::_>,
is_locking<boost::mpl::_>,
is_holder<boost::mpl::_>
>
>
>
>
{};
} /* namespace flyweights::detail */
template<
typename T,
typename Arg1,typename Arg2,typename Arg3,typename Arg4,typename Arg5
>
class flyweight
{
private:
typedef typename mpl::if_<
detail::is_value<T>,
T,
detail::default_value_policy<T>
>::type value_policy;
typedef typename detail::
flyweight_signature::bind<
Arg1,Arg2,Arg3,Arg4,Arg5
>::type args;
typedef typename parameter::binding<
args,tag<>,mpl::na
>::type tag_type;
typedef typename parameter::binding<
args,tracking<>,refcounted
>::type tracking_policy;
typedef typename parameter::binding<
args,factory<>,hashed_factory<>
>::type factory_specifier;
typedef typename parameter::binding<
args,locking<>,simple_locking
>::type locking_policy;
typedef typename parameter::binding<
args,holder<>,static_holder
>::type holder_specifier;
typedef typename detail::
flyweight_unmatched_signature::bind<
Arg1,Arg2,Arg3,Arg4,Arg5
>::type unmatched_args;
typedef typename parameter::binding<
unmatched_args,detail::unmatched_arg,
detail::unmatched_arg
>::type unmatched_arg_detected;
/* You have passed a type in the specification of a flyweight type that
* could not be interpreted as a valid argument.
*/
BOOST_MPL_ASSERT_MSG(
(is_same<unmatched_arg_detected,detail::unmatched_arg>::value),
INVALID_ARGUMENT_TO_FLYWEIGHT,
(flyweight));
typedef detail::flyweight_core<
value_policy,tag_type,tracking_policy,
factory_specifier,locking_policy,
holder_specifier
> core;
typedef typename core::handle_type handle_type;
public:
typedef typename value_policy::key_type key_type;
typedef typename value_policy::value_type value_type;
/* static data initialization */
static bool init(){return core::init();}
class initializer
{
public:
initializer():b(init()){}
private:
bool b;
};
/* construct/copy/destroy */
flyweight():h(core::insert(key_type())){}
flyweight(const flyweight& x):h(x.h){}
flyweight(flyweight& x):h(x.h){}
/* template ctors */
#define BOOST_FLYWEIGHT_PERFECT_FWD_NAME explicit flyweight
#define BOOST_FLYWEIGHT_PERFECT_FWD_BODY(n) \
:h(core::insert(BOOST_PP_ENUM_PARAMS(n,t))){}
#include <boost/flyweight/detail/perfect_fwd.hpp>
flyweight& operator=(const flyweight x){h=x.h;return *this;}
flyweight& operator=(const value_type& x){return operator=(flyweight(x));}
/* convertibility to underlying type */
const key_type& get_key()const{return core::key(h);}
const value_type& get()const{return core::value(h);}
operator const value_type&()const{return get();}
/* exact type equality */
friend bool operator==(const flyweight& x,const flyweight& y)
{
return &x.get()==&y.get();
}
/* modifiers */
void swap(flyweight& x){boost::swap(h,x.h);}
private:
handle_type h;
};
#define BOOST_FLYWEIGHT_TYPENAME_TEMPL_ARGS(n) \
typename Arg##n##1,typename Arg##n##2,typename Arg##n##3, \
typename Arg##n##4,typename Arg##n##5
#define BOOST_FLYWEIGHT_TEMPL_ARGS(n) \
Arg##n##1,Arg##n##2,Arg##n##3,Arg##n##4,Arg##n##5
/* Comparison. Unlike exact type comparison defined above, intertype
* comparison just forwards to the underlying objects.
*/
template<
typename T1,BOOST_FLYWEIGHT_TYPENAME_TEMPL_ARGS(1),
typename T2,BOOST_FLYWEIGHT_TYPENAME_TEMPL_ARGS(2)
>
bool operator==(
const flyweight<T1,BOOST_FLYWEIGHT_TEMPL_ARGS(1)>& x,
const flyweight<T2,BOOST_FLYWEIGHT_TEMPL_ARGS(2)>& y)
{
return x.get()==y.get();
}
template<
typename T1,BOOST_FLYWEIGHT_TYPENAME_TEMPL_ARGS(1),
typename T2,BOOST_FLYWEIGHT_TYPENAME_TEMPL_ARGS(2)
>
bool operator<(
const flyweight<T1,BOOST_FLYWEIGHT_TEMPL_ARGS(1)>& x,
const flyweight<T2,BOOST_FLYWEIGHT_TEMPL_ARGS(2)>& y)
{
return x.get()<y.get();
}
#if !defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING)
template<
typename T1,BOOST_FLYWEIGHT_TYPENAME_TEMPL_ARGS(1),
typename T2
>
bool operator==(
const flyweight<T1,BOOST_FLYWEIGHT_TEMPL_ARGS(1)>& x,const T2& y)
{
return x.get()==y;
}
template<
typename T1,
typename T2,BOOST_FLYWEIGHT_TYPENAME_TEMPL_ARGS(2)
>
bool operator==(
const T1& x,const flyweight<T2,BOOST_FLYWEIGHT_TEMPL_ARGS(2)>& y)
{
return x==y.get();
}
template<
typename T1,BOOST_FLYWEIGHT_TYPENAME_TEMPL_ARGS(1),
typename T2
>
bool operator<(
const flyweight<T1,BOOST_FLYWEIGHT_TEMPL_ARGS(1)>& x,const T2& y)
{
return x.get()<y;
}
template<
typename T1,
typename T2,BOOST_FLYWEIGHT_TYPENAME_TEMPL_ARGS(2)
>
bool operator<(
const T1& x,const flyweight<T2,BOOST_FLYWEIGHT_TEMPL_ARGS(2)>& y)
{
return x<y.get();
}
#endif /* !defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING) */
/* rest of comparison operators */
#define BOOST_FLYWEIGHT_COMPLETE_COMP_OPS(t,a1,a2) \
template<t> \
inline bool operator!=(const a1& x,const a2& y) \
{ \
return !(x==y); \
} \
\
template<t> \
inline bool operator>(const a1& x,const a2& y) \
{ \
return y<x; \
} \
\
template<t> \
inline bool operator>=(const a1& x,const a2& y) \
{ \
return !(x<y); \
} \
\
template<t> \
inline bool operator<=(const a1& x,const a2& y) \
{ \
return !(y<x); \
}
BOOST_FLYWEIGHT_COMPLETE_COMP_OPS(
typename T1 BOOST_PP_COMMA()
BOOST_FLYWEIGHT_TYPENAME_TEMPL_ARGS(1) BOOST_PP_COMMA()
typename T2 BOOST_PP_COMMA()
BOOST_FLYWEIGHT_TYPENAME_TEMPL_ARGS(2),
flyweight<
T1 BOOST_PP_COMMA() BOOST_FLYWEIGHT_TEMPL_ARGS(1)
>,
flyweight<
T2 BOOST_PP_COMMA() BOOST_FLYWEIGHT_TEMPL_ARGS(2)
>)
#if !defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING)
BOOST_FLYWEIGHT_COMPLETE_COMP_OPS(
typename T1 BOOST_PP_COMMA()
BOOST_FLYWEIGHT_TYPENAME_TEMPL_ARGS(1) BOOST_PP_COMMA()
typename T2,
flyweight<
T1 BOOST_PP_COMMA() BOOST_FLYWEIGHT_TEMPL_ARGS(1)
>,
T2)
BOOST_FLYWEIGHT_COMPLETE_COMP_OPS(
typename T1 BOOST_PP_COMMA()
typename T2 BOOST_PP_COMMA()
BOOST_FLYWEIGHT_TYPENAME_TEMPL_ARGS(2),
T1,
flyweight<
T2 BOOST_PP_COMMA() BOOST_FLYWEIGHT_TEMPL_ARGS(2)
>)
#endif /* !defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING) */
/* specialized algorithms */
template<typename T,BOOST_FLYWEIGHT_TYPENAME_TEMPL_ARGS(_)>
void swap(
flyweight<T,BOOST_FLYWEIGHT_TEMPL_ARGS(_)>& x,
flyweight<T,BOOST_FLYWEIGHT_TEMPL_ARGS(_)>& y)
{
x.swap(y);
}
template<
BOOST_TEMPLATED_STREAM_ARGS(ElemType,Traits)
BOOST_TEMPLATED_STREAM_COMMA
typename T,BOOST_FLYWEIGHT_TYPENAME_TEMPL_ARGS(_)
>
BOOST_TEMPLATED_STREAM(ostream,ElemType,Traits)& operator<<(
BOOST_TEMPLATED_STREAM(ostream,ElemType,Traits)& out,
const flyweight<T,BOOST_FLYWEIGHT_TEMPL_ARGS(_)>& x)
{
return out<<x.get();
}
template<
BOOST_TEMPLATED_STREAM_ARGS(ElemType,Traits)
BOOST_TEMPLATED_STREAM_COMMA
typename T,BOOST_FLYWEIGHT_TYPENAME_TEMPL_ARGS(_)
>
BOOST_TEMPLATED_STREAM(istream,ElemType,Traits)& operator>>(
BOOST_TEMPLATED_STREAM(istream,ElemType,Traits)& in,
flyweight<T,BOOST_FLYWEIGHT_TEMPL_ARGS(_)>& x)
{
typedef typename flyweight<
T,BOOST_FLYWEIGHT_TEMPL_ARGS(_)
>::value_type value_type;
/* value_type need not be default ctble but must be copy ctble */
value_type t(x.get());
in>>t;
x=t;
return in;
}
} /* namespace flyweights */
} /* namespace boost */
#undef BOOST_FLYWEIGHT_COMPLETE_COMP_OPS
#undef BOOST_FLYWEIGHT_TEMPL_ARGS
#undef BOOST_FLYWEIGHT_TYPENAME_TEMPL_ARGS
#if BOOST_WORKAROUND(BOOST_MSVC,BOOST_TESTED_AT(1400))
#pragma warning(pop)
#endif
#endif