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- use result_of<>

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- don't do that crazy argument deduction stuff--keep it simple!
- only include the nullary operator() when there is a result_type in T
- generate for any number of arguments


[SVN r1038]
This commit is contained in:
Douglas Gregor
2003-02-23 00:26:46 +00:00
parent 95d04d0f5a
commit c46809bbdf
2 changed files with 100 additions and 932 deletions
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574
include/boost/ref.hpp
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@@ -9,6 +9,8 @@
# include <boost/utility/addressof.hpp>
# include <boost/type_traits/ice.hpp>
# include <boost/type.hpp>
# include <boost/result_of.hpp>
# include <boost/pending/ct_if.hpp>
//
// ref.hpp - ref/cref, useful helper functions
@@ -26,541 +28,101 @@
// See http://www.boost.org/libs/bind/ref.html for documentation.
//
#ifndef BOOST_REF_NUM_ARGS
# define BOOST_REF_NUM_ARGS 10
#endif
namespace boost
{
struct deduce_ref_result {};
namespace detail { namespace ref {
// ------ has_result_type ---
template<typename T>
type_traits::yes_type has_result_type_helper(type<typename T::result_type>*);
template<typename T> type_traits::no_type has_result_type_helper(...);
template<typename T>
struct has_result_type
{
BOOST_STATIC_CONSTANT(bool,
value = (sizeof(has_result_type_helper<T>(0))
== sizeof(type_traits::yes_type)));
};
// ------ has_argument_type ---
template<typename T>
type_traits::yes_type
has_argument_type_helper(type<typename T::argument_type>*);
template<typename T> type_traits::no_type has_argument_type_helper(...);
template<typename T>
struct has_argument_type
{
BOOST_STATIC_CONSTANT(bool,
value = (sizeof(has_argument_type_helper<T>(0))
== sizeof(type_traits::yes_type)));
};
// ------ has_first_and_second_argument_types ---
template<typename T>
type_traits::yes_type has_first_and_second_argument_types_helper(
type<typename T::first_argument_type>*,
type<typename T::second_argument_type>*);
template<typename T>
type_traits::no_type has_first_and_second_argument_types_helper(...);
template<typename T>
struct has_first_and_second_argument_types
{
BOOST_STATIC_CONSTANT(bool,
value = (sizeof(has_first_and_second_argument_types_helper<T>(0, 0))
== sizeof(type_traits::yes_type)));
};
// ------ has_argN_type ---
template<typename T, int N>
struct has_argN_type
{
BOOST_STATIC_CONSTANT(bool, value = false);
};
#define BOOST_REF_HAS_ARGN_TYPE(N) \
template<typename T> \
type_traits::yes_type \
has_arg##N##_type_helper(type<typename T::arg##N##_type>*); \
\
template<typename T> type_traits::no_type has_arg##N##_type_helper(...); \
\
template<typename T> \
struct has_arg##N##_type \
{ \
BOOST_STATIC_CONSTANT(bool, \
value = (sizeof(has_arg##N##_type_helper<T>(0)) \
== sizeof(type_traits::yes_type))); \
}; \
\
template<typename T> \
struct has_argN_type<T, N> \
{ \
BOOST_STATIC_CONSTANT(bool, value = (has_arg##N##_type<T>::value)); \
};
BOOST_REF_HAS_ARGN_TYPE(1)
BOOST_REF_HAS_ARGN_TYPE(2)
BOOST_REF_HAS_ARGN_TYPE(3)
BOOST_REF_HAS_ARGN_TYPE(4)
BOOST_REF_HAS_ARGN_TYPE(5)
BOOST_REF_HAS_ARGN_TYPE(6)
BOOST_REF_HAS_ARGN_TYPE(7)
BOOST_REF_HAS_ARGN_TYPE(8)
BOOST_REF_HAS_ARGN_TYPE(9)
BOOST_REF_HAS_ARGN_TYPE(10)
#undef BOOST_REF_HAS_ARGN_TYPE
// ------ get_result_type0 ---
template<bool HasResultType, typename T> struct get_result_type0_impl;
template<typename T>
struct get_result_type0_impl<true, T>
{
typedef typename T::result_type type;
};
template<typename T>
struct get_result_type0_impl<false, T>
{
typedef void type;
};
template<typename T>
struct get_result_type0 :
public get_result_type0_impl<(has_result_type<T>::value), T>
{
};
// ------ get_result_type1 ---
template<bool HasResultType, typename T, typename T1>
struct get_result_type1_impl;
template<typename T, typename T1>
struct get_result_type1_impl<true, T, T1>
{
typedef typename T::result_type type;
};
template<typename T, typename T1>
struct get_result_type1_impl<false, T, T1>
{
typedef typename T::template sig<T1>::type type;
};
template<typename T, typename T1>
struct get_result_type1 :
public get_result_type1_impl<(has_result_type<T>::value), T, T1> {};
// ------ get_result_type2 ---
template<bool HasResultType, typename T, typename T1, typename T2>
struct get_result_type2_impl;
template<typename T, typename T1, typename T2>
struct get_result_type2_impl<true, T, T1, T2>
{
typedef typename T::result_type type;
};
template<typename T, typename T1, typename T2>
struct get_result_type2_impl<false, T, T1, T2>
{
typedef typename T::template sig<T1, T2>::type type;
};
template<typename T, typename T1, typename T2>
struct get_result_type2 :
public get_result_type2_impl<(has_result_type<T>::value), T, T1, T2> {};
// ------ get_result_type3 ---
template<bool HasResultType, typename T, typename T1, typename T2, typename T3>
struct get_result_type3_impl;
template<typename T, typename T1, typename T2, typename T3>
struct get_result_type3_impl<true, T, T1, T2, T3>
{
typedef typename T::result_type type;
};
template<typename T, typename T1, typename T2, typename T3>
struct get_result_type3_impl<false, T, T1, T2, T3>
{
typedef typename T::template sig<T1, T2, T3>::type type;
};
template<typename T, typename T1, typename T2, typename T3>
struct get_result_type3 :
public get_result_type3_impl<(has_result_type<T>::value), T, T1, T2, T3> {};
// ------ get_result_type ---
template<typename Result, typename Deducer>
struct get_result_type
{
typedef Result type;
};
template<typename Deducer>
struct get_result_type<deduce_ref_result, Deducer>
{
typedef typename Deducer::type type;
};
// ------ reference_wrapper_base
template<typename T, typename Result>
class reference_wrapper_base
class reference_wrapper_without_result_type
{
public:
template<typename F>
struct result_of
{
typedef typename result_of<F>::type type;
};
operator T& () const { return *(this->t_); }
T& get() const { return *(this->t_); }
T* get_pointer() const { return this->t_; }
typename get_result_type<Result, get_result_type0<T> >::type
operator()() const
{
return get()();
}
#define BOOST_PP_ITERATION_PARAMS_1 (3,(0,BOOST_REF_NUM_ARGS,<boost/detail/ref_iterate.hpp>))
#include BOOST_PP_ITERATE()
protected:
#if defined(BOOST_MSVC) && (BOOST_MSVC < 1300)
explicit reference_wrapper_base(T& t) : t_(&t) {}
explicit reference_wrapper_without_result_type(T& t) : t_(&t) {}
#else
explicit reference_wrapper_base(T& t) : t_(addressof(t)) {}
explicit reference_wrapper_without_result_type(T& t) : t_(addressof(t)) {}
#endif
private:
T* t_;
};
// ------ reference_wrapper_with_first_and_second_argument_types
template<typename T, typename Result>
class reference_wrapper_with_first_and_second_argument_types
: public reference_wrapper_base<T, Result>
#ifndef BOOST_NO_PARTIAL_SPECIALIZATION
template<typename T>
class reference_wrapper_with_result_type
{
typedef reference_wrapper_base<T, Result> inherited;
public:
typedef typename T::result_type result_type;
operator T& () const { return *(this->t_); }
T& get() const { return *(this->t_); }
T* get_pointer() const { return this->t_; }
result_type operator()() const { return get()(); }
#define BOOST_PP_ITERATION_PARAMS_1 (3,(0,BOOST_REF_NUM_ARGS,<boost/detail/ref_iterate.hpp>))
#include BOOST_PP_ITERATE()
protected:
explicit reference_wrapper_with_first_and_second_argument_types(T& t)
: inherited(t) {}
#if defined(BOOST_MSVC) && (BOOST_MSVC < 1300)
explicit reference_wrapper_with_result_type(T& t) : t_(&t) {}
#else
explicit reference_wrapper_with_result_type(T& t) : t_(addressof(t)) {}
#endif
public:
typedef typename T::first_argument_type first_argument_type;
typedef typename T::second_argument_type second_argument_type;
using inherited::operator();
typename get_result_type<Result,
get_result_type2<T, first_argument_type,
second_argument_type> >::type
operator()(const first_argument_type& a1,
const second_argument_type& a2) const
{
return this->get()(a1, a2);
}
private:
T* t_;
};
// ------ reference_wrapper_with_argument_type
template<typename T, typename Result, bool Available>
class maybe_also_first_and_second_argument_types;
template<typename T, typename Result>
class maybe_also_first_and_second_argument_types<T, Result, true>
: public reference_wrapper_with_first_and_second_argument_types<T, Result>
template<typename T>
class reference_wrapper_impl :
public ct_if<(has_result_type<T>::value),
reference_wrapper_with_result_type<T>,
reference_wrapper_without_result_type<T> >::type
{
typedef reference_wrapper_with_first_and_second_argument_types<T, Result>
typedef typename ct_if<(has_result_type<T>::value),
reference_wrapper_with_result_type<T>,
reference_wrapper_without_result_type<T> >::type
inherited;
protected:
explicit maybe_also_first_and_second_argument_types(T& t) : inherited(t) {}
public:
using inherited::operator();
reference_wrapper_impl(T& t) : inherited(t) {}
};
template<typename T, typename Result>
class maybe_also_first_and_second_argument_types<T, Result, false>
: public reference_wrapper_base<T, Result>
#else
template<typename T>
class reference_wrapper_impl : public reference_wrapper_without_result_type<T>
{
typedef reference_wrapper_base<T, Result> inherited;
typedef reference_wrapper_without_result_type<T> inherited;
protected:
explicit maybe_also_first_and_second_argument_types(T& t) : inherited(t) {}
public:
using inherited::operator();
};
template<typename T, typename Result>
class reference_wrapper_with_argument_type
: public maybe_also_first_and_second_argument_types<
T, Result,
(has_first_and_second_argument_types<T>::value)>
{
typedef maybe_also_first_and_second_argument_types<
T, Result,
(has_first_and_second_argument_types<T>::value)> inherited;
protected:
explicit reference_wrapper_with_argument_type(T& t) : inherited(t) {}
public:
typedef typename T::argument_type argument_type;
using inherited::operator();
typename get_result_type<Result, get_result_type1<T, argument_type> >::type
operator()(const argument_type& a1) const
{
return this->get()(a1);
}
};
// ------ reference_wrapper_with_argN_types
template<typename T, typename Result, int N, bool Exists>
class reference_wrapper_with_argN_types_impl;
template<typename T, typename Result, int N=1>
class reference_wrapper_with_argN_types
: public reference_wrapper_with_argN_types_impl<T, Result, N,
(has_argN_type<T, N>::value)>
{
typedef reference_wrapper_with_argN_types_impl<T, Result, N,
(has_argN_type<T, N>::value)>
inherited;
protected:
explicit reference_wrapper_with_argN_types(T& t) : inherited(t) {}
};
template<typename T, typename Result>
class reference_wrapper_with_argN_types_impl<T, Result, 1, true>
: public reference_wrapper_with_argN_types<T, Result, 2>
{
typedef reference_wrapper_with_argN_types<T, Result, 2> inherited;
protected:
explicit reference_wrapper_with_argN_types_impl(T& t) : inherited(t) {}
public:
typedef typename T::arg1_type arg1_type;
using inherited::operator();
typename get_result_type<Result, get_result_type1<T, arg1_type> >::type
operator()(arg1_type a1) const
{
return this->get()(a1);
}
};
template<typename T, typename Result>
class reference_wrapper_with_argN_types_impl<T, Result, 2, true>
: public reference_wrapper_with_argN_types<T, Result, 3>
{
typedef reference_wrapper_with_argN_types<T, Result, 3> inherited;
protected:
explicit reference_wrapper_with_argN_types_impl(T& t) : inherited(t) {}
public:
typedef typename T::arg1_type arg1_type;
typedef typename T::arg2_type arg2_type;
using inherited::operator();
typename get_result_type<Result,
get_result_type2<T, arg1_type, arg2_type> >::type
operator()(arg1_type a1, arg2_type a2) const
{
return this->get()(a1, a2);
}
};
template<typename T, typename Result>
class reference_wrapper_with_argN_types_impl<T, Result, 3, true>
: public reference_wrapper_with_argN_types<T, Result, 4>
{
typedef reference_wrapper_with_argN_types<T, Result, 4> inherited;
protected:
explicit reference_wrapper_with_argN_types_impl(T& t) : inherited(t) {}
public:
typedef typename T::arg1_type arg1_type;
typedef typename T::arg2_type arg2_type;
typedef typename T::arg3_type arg3_type;
using inherited::operator();
typename get_result_type<Result,
get_result_type3<T, arg1_type, arg2_type, arg3_type>
>::type
operator()(arg1_type a1, arg2_type a2, arg3_type a3) const
{
return this->get()(a1, a2, a3);
}
};
// Passed the number of arguments we know how to handle
template<typename T, typename Result, int N>
class reference_wrapper_with_argN_types_impl<T, Result, N, true>
: public reference_wrapper_base<T, Result>
{
typedef reference_wrapper_base<T, Result> inherited;
protected:
explicit reference_wrapper_with_argN_types_impl(T& t) : inherited(t) {}
public:
using inherited::operator();
};
// Underlying function object does not have any more argument types
template<typename T, typename Result, int N>
class reference_wrapper_with_argN_types_impl<T, Result, N, false>
: public reference_wrapper_base<T, Result>
{
typedef reference_wrapper_base<T, Result> inherited;
protected:
explicit reference_wrapper_with_argN_types_impl(T& t) : inherited(t) {}
public:
using inherited::operator();
};
// ------ reference_wrapper_with_deduced_args
template<typename T, typename Result>
class reference_wrapper_with_deduced_args :
public reference_wrapper_base<T, Result>
{
typedef reference_wrapper_base<T, Result> inherited;
protected:
explicit reference_wrapper_with_deduced_args(T& t) : inherited(t) {}
public:
using inherited::operator();
template<typename T1>
typename get_result_type<Result, get_result_type1<T, T1> >::type
operator()(T1& a1) const
{ return this->get()(a1); }
template<typename T1, typename T2>
typename get_result_type<Result, get_result_type2<T, T1, T2> >::type
operator()(T1& a1, T2& a2) const
{ return this->get()(a1, a2); }
template<typename T1, typename T2, typename T3>
typename get_result_type<Result, get_result_type3<T, T1, T2, T3> >::type
operator()(T1& a1, T2& a2, T3& a3) const
{ return this->get()(a1, a2, a3); }
};
// ------ reference_wrapper_operators
template<typename T, typename Result, bool Available>
class maybe_with_first_and_second_argument_types;
template<typename T, typename Result>
class maybe_with_first_and_second_argument_types<T, Result, true>
: public reference_wrapper_with_first_and_second_argument_types<T, Result>
{
typedef reference_wrapper_with_first_and_second_argument_types<T, Result>
inherited;
protected:
explicit maybe_with_first_and_second_argument_types(T& t) : inherited(t) {}
};
template<typename T, typename Result>
class maybe_with_first_and_second_argument_types<T, Result, false>
: public reference_wrapper_with_deduced_args<T, Result>
{
typedef reference_wrapper_with_deduced_args<T, Result> inherited;
protected:
explicit maybe_with_first_and_second_argument_types(T& t) : inherited(t) {}
};
template<typename T, typename Result, bool Available>
class maybe_with_argument_type;
template<typename T, typename Result>
class maybe_with_argument_type<T, Result, true>
: public reference_wrapper_with_argument_type<T, Result>
{
typedef reference_wrapper_with_argument_type<T, Result> inherited;
protected:
explicit maybe_with_argument_type(T& t) : inherited(t) {}
};
template<typename T, typename Result>
class maybe_with_argument_type<T, Result, false>
: public maybe_with_first_and_second_argument_types<
T, Result,
(has_first_and_second_argument_types<T>::value)>
{
typedef maybe_with_first_and_second_argument_types<
T, Result,
(has_first_and_second_argument_types<T>::value)>
inherited;
protected:
explicit maybe_with_argument_type(T& t) : inherited(t) {}
};
template<typename T, typename Result, bool Available>
class maybe_with_argN_types;
template<typename T, typename Result>
class maybe_with_argN_types<T, Result, true>
: public reference_wrapper_with_argN_types<T, Result>
{
typedef reference_wrapper_with_argN_types<T, Result> inherited;
protected:
explicit maybe_with_argN_types(T& t) : inherited(t) {}
};
template<typename T, typename Result>
class maybe_with_argN_types<T, Result, false>
: public maybe_with_argument_type<T, Result, (has_argument_type<T>::value)>
{
typedef maybe_with_argument_type<T, Result, (has_argument_type<T>::value)>
inherited;
protected:
explicit maybe_with_argN_types(T& t) : inherited(t) {}
};
template<typename T, typename Result>
class reference_wrapper_operators
: public maybe_with_argN_types<T, Result, (has_arg1_type<T>::value)>
{
typedef maybe_with_argN_types<T, Result, (has_arg1_type<T>::value)>
inherited;
protected:
explicit reference_wrapper_operators(T& t) : inherited(t) {}
reference_wrapper_impl(T& t) : inherited(t) {}
};
#endif
} } // end namespace detail::ref
template<class T, typename Result = deduce_ref_result>
class reference_wrapper
: public detail::ref::reference_wrapper_operators<T, Result>
template<class T>
class reference_wrapper : public detail::ref::reference_wrapper_impl<T>
{
typedef detail::ref::reference_wrapper_operators<T, Result> inherited;
typedef detail::ref::reference_wrapper_impl<T> inherited;
public:
typedef T type;
@@ -584,18 +146,6 @@ template<class T> inline reference_wrapper<T const> BOOST_REF_CONST cref(T const
return reference_wrapper<T const>(t);
}
template<typename Result, class T>
inline reference_wrapper<T, Result> BOOST_REF_CONST ref(T & t)
{
return reference_wrapper<T, Result>(t);
}
template<typename Result, class T>
inline reference_wrapper<T const, Result> BOOST_REF_CONST cref(T const & t)
{
return reference_wrapper<T const, Result>(t);
}
# undef BOOST_REF_CONST
# ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
@@ -606,8 +156,8 @@ class is_reference_wrapper
BOOST_STATIC_CONSTANT(bool, value = false);
};
template<typename T, typename Result>
class is_reference_wrapper<reference_wrapper<T, Result> >
template<typename T>
class is_reference_wrapper<reference_wrapper<T> >
{
public:
BOOST_STATIC_CONSTANT(bool, value = true);
@@ -620,8 +170,8 @@ class unwrap_reference
typedef T type;
};
template<typename T, typename Result>
class unwrap_reference<reference_wrapper<T, Result> >
template<typename T>
class unwrap_reference<reference_wrapper<T> >
{
public:
typedef T type;
@@ -640,9 +190,9 @@ namespace detail
no_reference_wrapper_t is_reference_wrapper_test(...);
template<typename T, typename Result>
template<typename T>
yes_reference_wrapper_t
is_reference_wrapper_test(type< reference_wrapper<T, Result> >);
is_reference_wrapper_test(type< reference_wrapper<T> >);
template<bool wrapped>
struct reference_unwrapper