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function_base.hpp, function_template.hpp:

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- Use a vtable instead of separate manager/invoker pointers, to shrink the
    size of a boost::function object to 8 bytes
  - Fix a problem with NULL member pointers


[SVN r32186]
This commit is contained in:
Douglas Gregor
2005-12-30 02:31:51 +00:00
parent c5e64fab99
commit 93c691fbdf
2 changed files with 244 additions and 153 deletions
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36
include/boost/function/function_base.hpp
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@ -386,6 +386,16 @@ namespace boost {
else return true;
}
#endif // BOOST_NO_SFINAE
/**
* Stores the "manager" portion of the vtable for a
* boost::function object.
*/
struct vtable_base
{
vtable_base() : manager(0) { }
any_pointer (*manager)(any_pointer, functor_manager_operation_type);
};
} // end namespace function
} // end namespace detail
@ -398,22 +408,22 @@ namespace boost {
class function_base
{
public:
function_base() : manager(0)
function_base() : vtable(0)
{
functor.obj_ptr = 0;
}
// Is this function empty?
bool empty() const { return !manager; }
bool empty() const { return !vtable; }
template<typename Functor>
Functor* target()
{
if (!manager) return 0;
if (!vtable) return 0;
detail::function::any_pointer result =
manager(detail::function::make_any_pointer(&typeid(Functor)),
detail::function::check_functor_type_tag);
vtable->manager(detail::function::make_any_pointer(&typeid(Functor)),
detail::function::check_functor_type_tag);
if (!result.obj_ptr) return 0;
else {
typedef typename detail::function::get_function_tag<Functor>::type tag;
@ -422,18 +432,17 @@ public:
}
template<typename Functor>
#if defined(BOOST_MSVC) && BOOST_WORKAROUND(BOOST_MSVC, < 1300)
const Functor* target( Functor * = 0 ) const
#else
const Functor* target() const
#endif
{
if (!manager) return 0;
if (!vtable) return 0;
detail::function::any_pointer result =
manager(detail::function::make_any_pointer(&typeid(Functor)),
detail::function::check_functor_type_tag);
vtable->manager(detail::function::make_any_pointer(&typeid(Functor)),
detail::function::check_functor_type_tag);
if (!result.obj_ptr) return 0;
else {
typedef typename detail::function::get_function_tag<Functor>::type tag;
@ -450,10 +459,11 @@ public:
bool contains(const F& f) const
{
#if defined(BOOST_MSVC) && BOOST_WORKAROUND(BOOST_MSVC, < 1300)
if (const F* fp = this->target( (F*)0 )) {
if (const F* fp = this->target( (F*)0 ))
#else
if (const F* fp = this->template target<F>()) {
if (const F* fp = this->template target<F>())
#endif
{
return function_equal(*fp, f);
} else {
return false;
@ -484,9 +494,7 @@ public:
#endif
public: // should be protected, but GCC 2.95.3 will fail to allow access
detail::function::any_pointer (*manager)(
detail::function::any_pointer,
detail::function::functor_manager_operation_type);
detail::function::vtable_base* vtable;
detail::function::any_pointer functor;
private: