lyx_mirror/boost/boost/function/function_base.hpp
Lars Gullik Bjønnes 2349a51b12 update to boost 1.32.0
git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@9274 a592a061-630c-0410-9148-cb99ea01b6c8
2004-11-20 09:08:45 +00:00

661 lines
20 KiB
C++

// Boost.Function library
// Copyright Douglas Gregor 2001-2004. Use, modification and
// distribution is subject to 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)
// For more information, see http://www.boost.org
#ifndef BOOST_FUNCTION_BASE_HEADER
#define BOOST_FUNCTION_BASE_HEADER
#include <stdexcept>
#include <string>
#include <memory>
#include <new>
#include <typeinfo>
#include <boost/config.hpp>
#include <boost/assert.hpp>
#include <boost/type_traits/is_integral.hpp>
#include <boost/type_traits/composite_traits.hpp>
#include <boost/type_traits/is_stateless.hpp>
#include <boost/ref.hpp>
#include <boost/pending/ct_if.hpp>
#include <boost/detail/workaround.hpp>
#ifndef BOOST_NO_SFINAE
# include "boost/utility/enable_if.hpp"
#else
# include "boost/mpl/bool.hpp"
#endif
#include <boost/function_equal.hpp>
// Borrowed from Boost.Python library: determines the cases where we
// need to use std::type_info::name to compare instead of operator==.
# if (defined(__GNUC__) && __GNUC__ >= 3) \
|| defined(_AIX) \
|| ( defined(__sgi) && defined(__host_mips))
# include <cstring>
# define BOOST_FUNCTION_COMPARE_TYPE_ID(X,Y) \
(std::strcmp((X).name(),(Y).name()) == 0)
# else
# define BOOST_FUNCTION_COMPARE_TYPE_ID(X,Y) ((X)==(Y))
#endif
#if defined(BOOST_MSVC) && BOOST_MSVC <= 1300 || defined(__ICL) && __ICL <= 600 || defined(__MWERKS__) && __MWERKS__ < 0x2406 && !defined(BOOST_STRICT_CONFIG)
# define BOOST_FUNCTION_TARGET_FIX(x) x
#else
# define BOOST_FUNCTION_TARGET_FIX(x)
#endif // not MSVC
#if defined(__sgi) && defined(_COMPILER_VERSION) && _COMPILER_VERSION <= 730 && !defined(BOOST_STRICT_CONFIG)
// Work around a compiler bug.
// boost::python::objects::function has to be seen by the compiler before the
// boost::function class template.
namespace boost { namespace python { namespace objects {
class function;
}}}
#endif
#if defined (BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) \
|| defined(BOOST_BCB_PARTIAL_SPECIALIZATION_BUG) \
|| !(BOOST_STRICT_CONFIG || !defined(__SUNPRO_CC) || __SUNPRO_CC > 0x540)
# define BOOST_FUNCTION_NO_FUNCTION_TYPE_SYNTAX
#endif
#define BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor,Type) \
typename ::boost::enable_if_c<(::boost::type_traits::ice_not< \
(::boost::is_integral<Functor>::value)>::value), \
Type>::type
#if !defined(BOOST_FUNCTION_NO_FUNCTION_TYPE_SYNTAX)
namespace boost {
#if defined(__sgi) && defined(_COMPILER_VERSION) && _COMPILER_VERSION <= 730 && !defined(BOOST_STRICT_CONFIG)
// The library shipping with MIPSpro 7.3.1.3m has a broken allocator<void>
class function_base;
template<typename Signature,
typename Allocator = std::allocator<function_base> >
class function;
#else
template<typename Signature, typename Allocator = std::allocator<void> >
class function;
#endif
template<typename Signature, typename Allocator>
inline void swap(function<Signature, Allocator>& f1,
function<Signature, Allocator>& f2)
{
f1.swap(f2);
}
} // end namespace boost
#endif // have partial specialization
namespace boost {
namespace detail {
namespace function {
/**
* A union of a function pointer and a void pointer. This is necessary
* because 5.2.10/6 allows reinterpret_cast<> to safely cast between
* function pointer types and 5.2.9/10 allows static_cast<> to safely
* cast between a void pointer and an object pointer. But it is not legal
* to cast between a function pointer and a void* (in either direction),
* so function requires a union of the two. */
union any_pointer
{
void* obj_ptr;
const void* const_obj_ptr;
void (*func_ptr)();
char data[1];
};
inline any_pointer make_any_pointer(void* o)
{
any_pointer p;
p.obj_ptr = o;
return p;
}
inline any_pointer make_any_pointer(const void* o)
{
any_pointer p;
p.const_obj_ptr = o;
return p;
}
inline any_pointer make_any_pointer(void (*f)())
{
any_pointer p;
p.func_ptr = f;
return p;
}
/**
* The unusable class is a placeholder for unused function arguments
* It is also completely unusable except that it constructable from
* anything. This helps compilers without partial specialization to
* handle Boost.Function objects returning void.
*/
struct unusable
{
unusable() {}
template<typename T> unusable(const T&) {}
};
/* Determine the return type. This supports compilers that do not support
* void returns or partial specialization by silently changing the return
* type to "unusable".
*/
template<typename T> struct function_return_type { typedef T type; };
template<>
struct function_return_type<void>
{
typedef unusable type;
};
// The operation type to perform on the given functor/function pointer
enum functor_manager_operation_type {
clone_functor_tag,
destroy_functor_tag,
check_functor_type_tag
};
// Tags used to decide between different types of functions
struct function_ptr_tag {};
struct function_obj_tag {};
struct member_ptr_tag {};
struct function_obj_ref_tag {};
struct stateless_function_obj_tag {};
template<typename F>
class get_function_tag
{
typedef typename ct_if<(is_pointer<F>::value),
function_ptr_tag,
function_obj_tag>::type ptr_or_obj_tag;
typedef typename ct_if<(is_member_pointer<F>::value),
member_ptr_tag,
ptr_or_obj_tag>::type ptr_or_obj_or_mem_tag;
typedef typename ct_if<(is_reference_wrapper<F>::value),
function_obj_ref_tag,
ptr_or_obj_or_mem_tag>::type or_ref_tag;
public:
typedef typename ct_if<(is_stateless<F>::value),
stateless_function_obj_tag,
or_ref_tag>::type type;
};
// The trivial manager does nothing but return the same pointer (if we
// are cloning) or return the null pointer (if we are deleting).
template<typename F>
struct trivial_manager
{
static inline any_pointer
get(any_pointer f, functor_manager_operation_type op)
{
switch (op) {
case clone_functor_tag: return f;
case destroy_functor_tag:
return make_any_pointer(reinterpret_cast<void*>(0));
case check_functor_type_tag:
{
std::type_info* t = static_cast<std::type_info*>(f.obj_ptr);
return BOOST_FUNCTION_COMPARE_TYPE_ID(typeid(F), *t)?
f
: make_any_pointer(reinterpret_cast<void*>(0));
}
}
// Clears up a warning with GCC 3.2.3
return make_any_pointer(reinterpret_cast<void*>(0));
}
};
/**
* The functor_manager class contains a static function "manage" which
* can clone or destroy the given function/function object pointer.
*/
template<typename Functor, typename Allocator>
struct functor_manager
{
private:
typedef Functor functor_type;
// For function pointers, the manager is trivial
static inline any_pointer
manager(any_pointer function_ptr,
functor_manager_operation_type op,
function_ptr_tag)
{
if (op == clone_functor_tag)
return function_ptr;
else
return make_any_pointer(static_cast<void (*)()>(0));
}
// For function object pointers, we clone the pointer to each
// function has its own version.
static inline any_pointer
manager(any_pointer function_obj_ptr,
functor_manager_operation_type op,
function_obj_tag)
{
#ifndef BOOST_NO_STD_ALLOCATOR
typedef typename Allocator::template rebind<functor_type>::other
allocator_type;
typedef typename allocator_type::pointer pointer_type;
#else
typedef functor_type* pointer_type;
#endif // BOOST_NO_STD_ALLOCATOR
# ifndef BOOST_NO_STD_ALLOCATOR
allocator_type allocator;
# endif // BOOST_NO_STD_ALLOCATOR
if (op == clone_functor_tag) {
functor_type* f =
static_cast<functor_type*>(function_obj_ptr.obj_ptr);
// Clone the functor
# ifndef BOOST_NO_STD_ALLOCATOR
pointer_type copy = allocator.allocate(1);
allocator.construct(copy, *f);
// Get back to the original pointer type
functor_type* new_f = static_cast<functor_type*>(copy);
# else
functor_type* new_f = new functor_type(*f);
# endif // BOOST_NO_STD_ALLOCATOR
return make_any_pointer(static_cast<void*>(new_f));
}
else {
/* Cast from the void pointer to the functor pointer type */
functor_type* f =
reinterpret_cast<functor_type*>(function_obj_ptr.obj_ptr);
# ifndef BOOST_NO_STD_ALLOCATOR
/* Cast from the functor pointer type to the allocator's pointer
type */
pointer_type victim = static_cast<pointer_type>(f);
// Destroy and deallocate the functor
allocator.destroy(victim);
allocator.deallocate(victim, 1);
# else
delete f;
# endif // BOOST_NO_STD_ALLOCATOR
return make_any_pointer(static_cast<void*>(0));
}
}
public:
/* Dispatch to an appropriate manager based on whether we have a
function pointer or a function object pointer. */
static any_pointer
manage(any_pointer functor_ptr, functor_manager_operation_type op)
{
if (op == check_functor_type_tag) {
std::type_info* type =
static_cast<std::type_info*>(functor_ptr.obj_ptr);
return (BOOST_FUNCTION_COMPARE_TYPE_ID(typeid(Functor), *type)?
functor_ptr
: make_any_pointer(reinterpret_cast<void*>(0)));
}
else {
typedef typename get_function_tag<functor_type>::type tag_type;
return manager(functor_ptr, op, tag_type());
}
}
};
// A type that is only used for comparisons against zero
struct useless_clear_type {};
#ifdef BOOST_NO_SFINAE
// These routines perform comparisons between a Boost.Function
// object and an arbitrary function object (when the last
// parameter is mpl::bool_<false>) or against zero (when the
// last parameter is mpl::bool_<true>). They are only necessary
// for compilers that don't support SFINAE.
template<typename Function, typename Functor>
bool
compare_equal(const Function& f, const Functor&, int, mpl::bool_<true>)
{ return f.empty(); }
template<typename Function, typename Functor>
bool
compare_not_equal(const Function& f, const Functor&, int,
mpl::bool_<true>)
{ return !f.empty(); }
template<typename Function, typename Functor>
bool
compare_equal(const Function& f, const Functor& g, long,
mpl::bool_<false>)
{
if (const Functor* fp = f.template target<Functor>())
return function_equal(*fp, g);
else return false;
}
template<typename Function, typename Functor>
bool
compare_equal(const Function& f, const reference_wrapper<Functor>& g,
int, mpl::bool_<false>)
{
if (const Functor* fp = f.template target<Functor>())
return fp == g.get_pointer();
else return false;
}
template<typename Function, typename Functor>
bool
compare_not_equal(const Function& f, const Functor& g, long,
mpl::bool_<false>)
{
if (const Functor* fp = f.template target<Functor>())
return !function_equal(*fp, g);
else return true;
}
template<typename Function, typename Functor>
bool
compare_not_equal(const Function& f,
const reference_wrapper<Functor>& g, int,
mpl::bool_<false>)
{
if (const Functor* fp = f.template target<Functor>())
return fp != g.get_pointer();
else return true;
}
#endif // BOOST_NO_SFINAE
} // end namespace function
} // end namespace detail
/**
* The function_base class contains the basic elements needed for the
* function1, function2, function3, etc. classes. It is common to all
* functions (and as such can be used to tell if we have one of the
* functionN objects).
*/
class function_base
{
public:
function_base() : manager(0)
{
functor.obj_ptr = 0;
}
// Is this function empty?
bool empty() const { return !manager; }
template<typename Functor>
Functor* target()
{
if (!manager) return 0;
detail::function::any_pointer result =
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;
return get_functor_pointer<Functor>(tag(), 0);
}
}
template<typename Functor>
const Functor* target() const
{
if (!manager) return 0;
detail::function::any_pointer result =
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;
return get_functor_pointer<Functor>(tag(), 0);
}
}
template<typename F>
bool contains(const F& f) const
{
if (const F* fp = this->template target<F>()) {
return function_equal(*fp, f);
} else {
return false;
}
}
#if defined(__GNUC__) && __GNUC__ == 3 && __GNUC_MINOR__ <= 3
// GCC 3.3 and newer cannot copy with the global operator==, due to
// problems with instantiation of function return types before it
// has been verified that the argument types match up.
template<typename Functor>
BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor, bool)
operator==(Functor g) const
{
if (const Functor* fp = target<Functor>())
return function_equal(*fp, g);
else return false;
}
template<typename Functor>
BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor, bool)
operator!=(Functor g) const
{
if (const Functor* fp = target<Functor>())
return !function_equal(*fp, g);
else return true;
}
#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::any_pointer functor;
private:
template<typename Functor>
Functor* get_functor_pointer(detail::function::function_ptr_tag, int)
{ return reinterpret_cast<Functor*>(&functor.func_ptr); }
template<typename Functor, typename Tag>
Functor* get_functor_pointer(Tag, long)
{ return static_cast<Functor*>(functor.obj_ptr); }
template<typename Functor>
const Functor*
get_functor_pointer(detail::function::function_ptr_tag, int) const
{ return reinterpret_cast<const Functor*>(&functor.func_ptr); }
template<typename Functor, typename Tag>
const Functor* get_functor_pointer(Tag, long) const
{ return static_cast<const Functor*>(functor.const_obj_ptr); }
};
/**
* The bad_function_call exception class is thrown when a boost::function
* object is invoked
*/
class bad_function_call : public std::runtime_error
{
public:
bad_function_call() : std::runtime_error("call to empty boost::function") {}
};
#ifndef BOOST_NO_SFINAE
inline bool operator==(const function_base& f,
detail::function::useless_clear_type*)
{
return f.empty();
}
inline bool operator!=(const function_base& f,
detail::function::useless_clear_type*)
{
return !f.empty();
}
inline bool operator==(detail::function::useless_clear_type*,
const function_base& f)
{
return f.empty();
}
inline bool operator!=(detail::function::useless_clear_type*,
const function_base& f)
{
return !f.empty();
}
#endif
#ifdef BOOST_NO_SFINAE
// Comparisons between boost::function objects and arbitrary function objects
template<typename Functor>
inline bool operator==(const function_base& f, Functor g)
{
typedef mpl::bool_<(is_integral<Functor>::value)> integral;
return detail::function::compare_equal(f, g, 0, integral());
}
template<typename Functor>
inline bool operator==(Functor g, const function_base& f)
{
typedef mpl::bool_<(is_integral<Functor>::value)> integral;
return detail::function::compare_equal(f, g, 0, integral());
}
template<typename Functor>
inline bool operator!=(const function_base& f, Functor g)
{
typedef mpl::bool_<(is_integral<Functor>::value)> integral;
return detail::function::compare_not_equal(f, g, 0, integral());
}
template<typename Functor>
inline bool operator!=(Functor g, const function_base& f)
{
typedef mpl::bool_<(is_integral<Functor>::value)> integral;
return detail::function::compare_not_equal(f, g, 0, integral());
}
#else
# if !(defined(__GNUC__) && __GNUC__ == 3 && __GNUC_MINOR__ <= 3)
// Comparisons between boost::function objects and arbitrary function
// objects. GCC 3.3 and before has an obnoxious bug that prevents this
// from working.
template<typename Functor>
BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor, bool)
operator==(const function_base& f, Functor g)
{
if (const Functor* fp = f.template target<Functor>())
return function_equal(*fp, g);
else return false;
}
template<typename Functor>
BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor, bool)
operator==(Functor g, const function_base& f)
{
if (const Functor* fp = f.template target<Functor>())
return function_equal(g, *fp);
else return false;
}
template<typename Functor>
BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor, bool)
operator!=(const function_base& f, Functor g)
{
if (const Functor* fp = f.template target<Functor>())
return !function_equal(*fp, g);
else return true;
}
template<typename Functor>
BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor, bool)
operator!=(Functor g, const function_base& f)
{
if (const Functor* fp = f.template target<Functor>())
return !function_equal(g, *fp);
else return true;
}
# endif
template<typename Functor>
BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor, bool)
operator==(const function_base& f, reference_wrapper<Functor> g)
{
if (const Functor* fp = f.template target<Functor>())
return fp == g.get_pointer();
else return false;
}
template<typename Functor>
BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor, bool)
operator==(reference_wrapper<Functor> g, const function_base& f)
{
if (const Functor* fp = f.template target<Functor>())
return g.get_pointer() == fp;
else return false;
}
template<typename Functor>
BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor, bool)
operator!=(const function_base& f, reference_wrapper<Functor> g)
{
if (const Functor* fp = f.template target<Functor>())
return fp != g.get_pointer();
else return true;
}
template<typename Functor>
BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL(Functor, bool)
operator!=(reference_wrapper<Functor> g, const function_base& f)
{
if (const Functor* fp = f.template target<Functor>())
return g.get_pointer() != fp;
else return true;
}
#endif // Compiler supporting SFINAE
namespace detail {
namespace function {
inline bool has_empty_target(const function_base* f)
{
return f->empty();
}
#if BOOST_WORKAROUND(BOOST_MSVC, <= 1310)
inline bool has_empty_target(const void*)
{
return false;
}
#else
inline bool has_empty_target(...)
{
return false;
}
#endif
} // end namespace function
} // end namespace detail
} // end namespace boost
#undef BOOST_FUNCTION_ENABLE_IF_NOT_INTEGRAL
#undef BOOST_FUNCTION_COMPARE_TYPE_ID
#endif // BOOST_FUNCTION_BASE_HEADER