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Added support for target_type() member function (returns an std::type_info of

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the underlying function object) and casting to retrieve the underyling target.


[SVN r11360]
This commit is contained in:
Douglas Gregor
2001-10-08 13:32:24 +00:00
parent 62d3c6d426
commit 1d4282c706
2 changed files with 156 additions and 6 deletions
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142
include/boost/function/function_template.hpp
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@ -46,6 +46,8 @@ namespace boost {
virtual R call(BOOST_FUNCTION_PARMS) const = 0;
virtual BOOST_FUNCTION_INVOKER_BASE* clone() const = 0;
virtual void destroy(BOOST_FUNCTION_INVOKER_BASE*) = 0;
virtual const std::type_info& type() const = 0;
virtual any_pointer pointer() const = 0;
};
#endif // BOOST_FUNCTION_USE_VIRTUAL_FUNCTIONS
@ -113,8 +115,18 @@ namespace boost {
# endif // BOOST_NO_STD_ALLOCATOR
}
virtual const std::type_info& type() const
{
return typeid(FunctionPtr);
}
virtual any_pointer pointer() const
{
return any_pointer(reinterpret_cast<void (*)()>(function_ptr));
}
private:
FunctionPtr function_ptr;
mutable FunctionPtr function_ptr;
#else
static R invoke(any_pointer function_ptr BOOST_FUNCTION_COMMA
BOOST_FUNCTION_PARMS)
@ -190,8 +202,18 @@ namespace boost {
# endif // BOOST_NO_STD_ALLOCATOR
}
virtual const std::type_info& type() const
{
return typeid(FunctionPtr);
}
virtual any_pointer pointer() const
{
return any_pointer(reinterpret_cast<void (*)()>(function_ptr));
}
private:
FunctionPtr function_ptr;
mutable FunctionPtr function_ptr;
# else
static unusable invoke(any_pointer function_ptr BOOST_FUNCTION_COMMA
BOOST_FUNCTION_PARMS)
@ -268,6 +290,16 @@ namespace boost {
#endif // BOOST_NO_STD_ALLOCATOR
}
virtual const std::type_info& type() const
{
return typeid(FunctionObj);
}
virtual any_pointer pointer() const
{
return any_pointer(&function_obj);
}
private:
mutable FunctionObj function_obj;
#else
@ -346,6 +378,16 @@ namespace boost {
# endif // BOOST_NO_STD_ALLOCATOR
}
virtual const std::type_info& type() const
{
return typeid(FunctionObj);
}
virtual any_pointer pointer() const
{
return any_pointer(&function_obj);
}
private:
mutable FunctionObj function_obj;
# else
@ -601,7 +643,73 @@ namespace boost {
#endif // BOOST_FUNCTION_USE_VIRTUAL_FUNCTIONS
}
const std::type_info& target_type() const
{
if (this->empty())
return typeid(void);
else {
#ifdef BOOST_FUNCTION_USE_VIRTUAL_FUNCTIONS
impl_type* i = reinterpret_cast<impl_type*>(impl);
return i->type();
#else
detail::function::any_pointer p =
manager(functor, detail::function::retrieve_type_info);
return *static_cast<const std::type_info*>(p.const_obj_ptr);
#endif // BOOST_FUNCTION_USE_VIRTUAL_FUNCTIONS
}
}
template<typename To>
To& cast(To* = 0)
{
assert(typeid(To) != typeid(void));
assert(typeid(To) == this->target_type());
typedef typename detail::function::IF<(is_pointer<To>::value),
detail::function::function_ptr_tag,
detail::function::function_obj_tag>::type tag;
#ifdef BOOST_FUNCTION_USE_VIRTUAL_FUNCTIONS
impl_type* i = reinterpret_cast<impl_type*>(impl);
return cast_helper<To>(i->pointer(), tag());
#else
return cast_helper<To>(functor, tag());
#endif // BOOST_FUNCTION_USE_VIRTUAL_FUNCTIONS
}
template<typename To>
const To& cast(To* = 0) const
{
assert(typeid(To) != typeid(void));
assert(typeid(To) == this->target_type());
typedef typename detail::function::IF<(is_pointer<To>::value),
detail::function::function_ptr_tag,
detail::function::function_obj_tag>::type tag;
#ifdef BOOST_FUNCTION_USE_VIRTUAL_FUNCTIONS
impl_type* i = reinterpret_cast<impl_type*>(impl);
return cast_helper<To>(i->pointer(), tag());
#else
return cast_helper<To>(functor, tag());
#endif // BOOST_FUNCTION_USE_VIRTUAL_FUNCTIONS
}
private:
template<typename To>
To& cast_helper(detail::function::any_pointer p,
detail::function::function_ptr_tag,
To* = 0) const
{
return reinterpret_cast<To>(p.func_ptr);
}
template<typename To>
To& cast_helper(detail::function::any_pointer p,
detail::function::function_obj_tag,
To* = 0) const
{
return *static_cast<To*>(p.obj_ptr);
}
void assign_to_own(const BOOST_FUNCTION_FUNCTION& f)
{
if (!f.empty()) {
@ -731,6 +839,36 @@ namespace boost {
{
f1.swap(f2);
}
template<typename To, typename R
BOOST_FUNCTION_COMMA BOOST_FUNCTION_TEMPLATE_PARMS ,
typename Policy, typename Mixin, typename Allocator>
inline To& function_cast(BOOST_FUNCTION_FUNCTION<
R BOOST_FUNCTION_COMMA
BOOST_FUNCTION_TEMPLATE_ARGS ,
Policy,
Mixin,
Allocator
>& f,
To* = 0)
{
return f.template cast<To>();
}
template<typename To, typename R
BOOST_FUNCTION_COMMA BOOST_FUNCTION_TEMPLATE_PARMS ,
typename Policy, typename Mixin, typename Allocator>
inline const To& function_cast(const BOOST_FUNCTION_FUNCTION<
R BOOST_FUNCTION_COMMA
BOOST_FUNCTION_TEMPLATE_ARGS ,
Policy,
Mixin,
Allocator
>& f,
To* = 0)
{
return f.template cast<To>();
}
}
// Cleanup after ourselves...