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/* /////////////////////////////////////////////////////////////////////////
* File: comstl/conversion/interface_cast.hpp * * Purpose: Safe interface casting functions. * * Created: 25th June 2002 * Updated: 6th May 2010 * * Home: http://stlsoft.org/
* * Copyright (c) 2002-2010, Matthew Wilson and Synesis Software * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * - Redistributions of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. * - Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * - Neither the name(s) of Matthew Wilson and Synesis Software nor the names of * any contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * * ////////////////////////////////////////////////////////////////////// */
/** \file comstl/conversion/interface_cast.hpp
* * \brief [C++ only] Definition of the * comstl::interface_cast, * comstl::interface_cast_test * and * comstl::try_interface_cast * cast functions * and the * comstl::interface_cast_addref * and * comstl::interface_cast_noaddref * cast classes. * (\ref group__library__conversion "Conversion" Library). */
#ifndef COMSTL_INCL_COMSTL_CONVERSION_HPP_INTERFACE_CAST
#define COMSTL_INCL_COMSTL_CONVERSION_HPP_INTERFACE_CAST
#ifndef STLSOFT_DOCUMENTATION_SKIP_SECTION
# define COMSTL_VER_COMSTL_CONVERSION_HPP_INTERFACE_CAST_MAJOR 5
# define COMSTL_VER_COMSTL_CONVERSION_HPP_INTERFACE_CAST_MINOR 2
# define COMSTL_VER_COMSTL_CONVERSION_HPP_INTERFACE_CAST_REVISION 4
# define COMSTL_VER_COMSTL_CONVERSION_HPP_INTERFACE_CAST_EDIT 117
#endif /* !STLSOFT_DOCUMENTATION_SKIP_SECTION */
/* /////////////////////////////////////////////////////////////////////////
* Compatibility */
/*
[Incompatibilies-start] STLSOFT_COMPILER_IS_MSVC: _MSC_VER<1200 [Incompatibilies-end] */
/* /////////////////////////////////////////////////////////////////////////
* Includes */
#ifndef COMSTL_INCL_COMSTL_H_COMSTL
# include <comstl/comstl.h>
#endif /* !COMSTL_INCL_COMSTL_H_COMSTL */
#if defined(STLSOFT_COMPILER_IS_MSVC) && \
_MSC_VER < 1200 # error comstl/conversion/interface_cast.hpp is not compatible with Visual C++ 5.0 or earlier
#endif /* compiler */
#ifndef COMSTL_INCL_COMSTL_UTIL_H_REFCOUNT_FUNCTIONS
# include <comstl/util/refcount_functions.h>
#endif /* !COMSTL_INCL_COMSTL_UTIL_H_REFCOUNT_FUNCTIONS */
#ifndef COMSTL_INCL_COMSTL_UTIL_HPP_INTERFACE_TRAITS
# include <comstl/util/interface_traits.hpp>
#endif /* !COMSTL_INCL_COMSTL_UTIL_HPP_INTERFACE_TRAITS */
#ifdef STLSOFT_CF_EXCEPTION_SUPPORT
# ifndef COMSTL_INCL_COMSTL_ERROR_HPP_BAD_INTERFACE_CAST
# include <comstl/error/bad_interface_cast.hpp>
# endif /* !COMSTL_INCL_COMSTL_ERROR_HPP_BAD_INTERFACE_CAST */
#endif /* STLSOFT_CF_EXCEPTION_SUPPORT */
#ifndef STLSOFT_INCL_STLSOFT_SMARTPTR_HPP_REF_PTR
# include <stlsoft/smartptr/ref_ptr.hpp>
#endif /* !STLSOFT_INCL_STLSOFT_SMARTPTR_HPP_REF_PTR */
#ifndef STLSOFT_INCL_STLSOFT_UTIL_HPP_OPERATOR_BOOL
# include <stlsoft/util/operator_bool.hpp>
#endif /* !STLSOFT_INCL_STLSOFT_UTIL_HPP_OPERATOR_BOOL */
/* /////////////////////////////////////////////////////////////////////////
* Namespace */
#ifndef _COMSTL_NO_NAMESPACE
# if defined(_STLSOFT_NO_NAMESPACE) || \
defined(STLSOFT_DOCUMENTATION_SKIP_SECTION) /* There is no stlsoft namespace, so must define ::comstl */ namespace comstl { # else
/* Define stlsoft::comstl_project */
namespace stlsoft {
namespace comstl_project {
# endif /* _STLSOFT_NO_NAMESPACE */
#endif /* !_COMSTL_NO_NAMESPACE */
/* /////////////////////////////////////////////////////////////////////////
* Functions */
// This helper converts from an interface pointer to itself.
//
// It explicitly takes and returns pointer so that it disambiguates from any
// overload that takes an interface wrapper instance by value/reference.
template <ss_typename_param_k I> inline I* simple_interface_cast(I* pi) { return pi; }
/* /////////////////////////////////////////////////////////////////////////
* Functionals */
/** \brief A function class that does not throw any exceptions. For use with
* comstl::interface_cast_noaddref and comstl::interface_cast_addref cast * classes. * * \ingroup group__library__conversion */ // [[synesis:class:exception-policy: ignore_interface_cast_exception]]
struct ignore_interface_cast_exception { public: /// The exception type
struct thrown_type { };
public: /// The function call operator, which does not throw an exception
///
/// \param hr The HRESULT that caused the error
/// \param riid The REFIID that could not be acquired
void operator ()(HRESULT hr, REFIID riid) stlsoft_throw_0() { STLSOFT_SUPPRESS_UNUSED(hr); STLSOFT_SUPPRESS_UNUSED(riid);
// Do nothing
} };
#ifdef STLSOFT_CF_EXCEPTION_SUPPORT
/** \brief A function class that throws the
* \link comstl::bad_interface_cast bad_interface_cast\endlink exception * class. For use with * comstl::interface_cast_noaddref and comstl::interface_cast_addref cast * classes. * * \ingroup group__library__conversion */ // [[synesis:class:exception-policy: throw_bad_interface_cast_exception]]
struct throw_bad_interface_cast_exception { public: /// The exception type
typedef bad_interface_cast thrown_type;
public: /// The function call operator, which throws the exception
///
/// \param hr The HRESULT that caused the error
/// \param riid The REFIID that could not be acquired
void operator ()(HRESULT hr, REFIID riid) stlsoft_throw_1(bad_interface_cast) { STLSOFT_THROW_X(bad_interface_cast(riid, hr)); } };
#endif /* STLSOFT_CF_EXCEPTION_SUPPORT */
/** \brief A function class that calls Release() on the interface. For use with
* comstl::interface_cast_noaddref and comstl::interface_cast_addref cast * classes. * * \ingroup group__library__conversion */ template <ss_typename_param_k I> struct noaddref_release { public: /// The function call operator, that calls Release() on the interface
///
/// \param pi The interface pointer
void operator ()(I pi) { release(pi); } };
/** \brief A function class that does not call Release() on the interface. For use with
* comstl::interface_cast_noaddref and comstl::interface_cast_addref cast * classes. * * \ingroup group__library__conversion */ template <ss_typename_param_k I> struct addref_release { public: /// The function call operator, which does not call Release() on the interface
///
/// \param pi The interface pointer
void operator ()(I pi) { STLSOFT_SUPPRESS_UNUSED(pi); } };
/* /////////////////////////////////////////////////////////////////////////
* Raw-pointer safety * * Alas this requires partial template specialisation, so is not available in * all environments. */
#ifdef STLSOFT_CF_TEMPLATE_PARTIAL_SPECIALISATION_SUPPORT
# ifndef STLSOFT_DOCUMENTATION_SKIP_SECTION
template <ss_typename_param_k I> struct interface_pointer_traits;
template <ss_typename_param_k I> struct interface_pointer_traits<I*> { typedef I interface_type; };
# endif /* !STLSOFT_DOCUMENTATION_SKIP_SECTION */
/** \brief A veneer interface that hides the AddRef() and Release() methods.
* For use with comstl::interface_cast_noaddref and * comstl::interface_cast_addref cast classes. * * \ingroup group__library__conversion */ template <ss_typename_param_k I> interface protect_refcount : public I { private: STDMETHOD_(ULONG, AddRef)() { I* pi = static_cast<I*>(this);
return pi->AddRef(); } STDMETHOD_(ULONG, Release)() { I* pi = static_cast<I*>(this);
return pi->Release(); } };
#endif /* STLSOFT_CF_TEMPLATE_PARTIAL_SPECIALISATION_SUPPORT */
/* /////////////////////////////////////////////////////////////////////////
* Classes */
/** \brief Base class for the interface cast classes
* comstl::interface_cast_noaddref and comstl::interface_cast_addref. * * \ingroup group__library__conversion * * This class serves only as a base, and cannot be used in isolation * * \param I The interface pointer type * \param R The release type * \param X The exception type */ // [[synesis:class:implementation: comstl::interface_cast_base]]
template< ss_typename_param_k I , ss_typename_param_k R , ss_typename_param_k X > class interface_cast_base { /// \name Member Types
/// @{
public: /// The interface pointer type
typedef I interface_pointer_type; #ifdef STLSOFT_CF_TEMPLATE_PARTIAL_SPECIALISATION_SUPPORT
/// The interface type
typedef ss_typename_type_k interface_pointer_traits<I>::interface_type interface_type; #endif /* STLSOFT_CF_TEMPLATE_PARTIAL_SPECIALISATION_SUPPORT */
/// The release type
typedef R release_type; /// The exception type
typedef X exception_policy_type; /// The thrown type
typedef ss_typename_type_k exception_policy_type::thrown_type thrown_type; /// The type of the current parameterisation
typedef interface_cast_base<I, R, X> class_type; /// @}
/// \name Member Constants
/// @{
protected: enum NullThrowPermission { allowNull , throwOnNull }; /// @}
/// \name Construction
/// @{
protected: /// Constructor that attempts the speculative cast
#ifdef STLSOFT_CF_MEMBER_TEMPLATE_CTOR_SUPPORT
template <ss_typename_param_k J> ss_explicit_k interface_cast_base(J &j, NullThrowPermission permission) : m_pi(do_cast(simple_interface_cast(j), permission)) {} #else /* ? STLSOFT_CF_MEMBER_TEMPLATE_CTOR_SUPPORT */
ss_explicit_k interface_cast_base(LPUNKNOWN punk, NullThrowPermission permission) : m_pi(do_cast(punk, permission)) {} #endif /* STLSOFT_CF_MEMBER_TEMPLATE_CTOR_SUPPORT */
/// Constructor that directly casts (without calling QueryInterface())
ss_explicit_k interface_cast_base(interface_pointer_type pi) : m_pi(pi) { addref(m_pi); }
/// Releases the acquired interface pointer according to the \c release_type policy
~interface_cast_base() stlsoft_throw_0() { if(NULL != m_pi) { release_type()(m_pi); } } /// @}
/// \name Implementation
/// @{
private: /// Perform the cast, throwing the \c exception_policy_type's \c thrown_type if the
/// requested interface cannot be acquired.
///
/// \param punk The interface pointer to cast
/// \return The converted interface pointer
static interface_pointer_type do_cast(LPUNKNOWN punk, NullThrowPermission permission) stlsoft_throw_1(thrown_type) { interface_pointer_type pi;
if(NULL == punk) { if(throwOnNull == permission) { exception_policy_type()(E_INVALIDARG, IID_traits<interface_pointer_type>().iid());
COMSTL_MESSAGE_ASSERT("The derived class does not support null pointers, but the exception policy failed to throw an exception: the program's behaviour will be undefined!", 0); }
pi = NULL; } else { REFIID iid = IID_traits<interface_pointer_type>().iid(); HRESULT hr = punk->QueryInterface(iid, reinterpret_cast<void**>(&pi));
if(FAILED(hr)) { exception_policy_type()(hr, iid);
pi = NULL; } }
return pi; } /// @}
/// \name Accessors
/// @{
protected: /// Returns a non-mutating reference to the acquired interface pointer
interface_pointer_type const& get_pointer_() { return m_pi; }
/// Returns a copy of the acquired interface pointer
interface_pointer_type get_pointer_() const { return m_pi; } /// @}
/// \name Members
/// @{
private: interface_pointer_type const m_pi; /// @}
/// \name Not to be implemented
/// @{
protected: interface_cast_base(class_type const& rhs); private: class_type const& operator =(class_type const& rhs); /// @}
};
#ifdef STLSOFT_CF_EXCEPTION_SUPPORT
/** \brief Interface cast for raw pointers that does not add a net reference count
* * \ingroup group__library__conversion * * This class provides a cast between interface pointers, but does not add a net reference count * * \param I The interface pointer type * \param X The exception type * * \note This class is not defined when exception-handling is not supported. */ // [[synesis:class:cast: comstl::interface_cast_noaddref]]
template< ss_typename_param_k I , ss_typename_param_k X = throw_bad_interface_cast_exception > class interface_cast_noaddref : protected interface_cast_base<I, noaddref_release<I>, X> { private: // Member Types
typedef interface_cast_base<I, noaddref_release<I>, X> parent_class_type; public: /// The type of the current parameterisation
typedef interface_cast_noaddref<I, X> class_type; /// The interface pointer type
typedef ss_typename_type_k parent_class_type::interface_pointer_type interface_pointer_type; # ifdef STLSOFT_CF_TEMPLATE_PARTIAL_SPECIALISATION_SUPPORT
/// The interface type
typedef ss_typename_type_k parent_class_type::interface_type interface_type; typedef protect_refcount<interface_type>* protected_interface_pointer_type; # else /* ? STLSOFT_CF_TEMPLATE_PARTIAL_SPECIALISATION_SUPPORT */
typedef interface_pointer_type protected_interface_pointer_type; # endif /* STLSOFT_CF_TEMPLATE_PARTIAL_SPECIALISATION_SUPPORT */
public: // Construction
/// Constructor that attempts the speculative cast
# ifdef STLSOFT_CF_MEMBER_TEMPLATE_CTOR_SUPPORT
template <ss_typename_param_k J> ss_explicit_k interface_cast_noaddref(J &j) : parent_class_type(j, parent_class_type::throwOnNull) { COMSTL_MESSAGE_ASSERT("Cannot initialise with a null pointer. Program behaviour will be undefined when it this instance is dereference", NULL != this->parent_class_type::get_pointer_()); } # else /* ? STLSOFT_CF_MEMBER_TEMPLATE_CTOR_SUPPORT */
ss_explicit_k interface_cast_noaddref(LPUNKNOWN punk) : parent_class_type(punk, parent_class_type::throwOnNull) { COMSTL_MESSAGE_ASSERT("Cannot initialise with a null pointer. Program behaviour will be undefined when it this instance is dereference", NULL != this->parent_class_type::get_pointer_()); } # endif /* STLSOFT_CF_MEMBER_TEMPLATE_CTOR_SUPPORT */
/// Constructor that directly casts (without calling QueryInterface())
ss_explicit_k interface_cast_noaddref(interface_pointer_type pi) : parent_class_type(pi, parent_class_type::throwOnNull) { COMSTL_MESSAGE_ASSERT("Cannot initialise with a null pointer. Program behaviour will be undefined when it this instance is dereference", NULL != this->parent_class_type::get_pointer_()); }
# ifndef STLSOFT_DOCUMENTATION_SKIP_SECTION
~interface_cast_noaddref() stlsoft_throw_0() {} // We need to provide this to persuade VC6 to call the parent class dtor
# endif /* !STLSOFT_DOCUMENTATION_SKIP_SECTION */
// Accessors
public: /// Access the members of the interface
protected_interface_pointer_type operator -> () const { COMSTL_MESSAGE_ASSERT("Attempting to dereference null pointer. Exception model should not be null", NULL != this->parent_class_type::get_pointer_());
return static_cast<protected_interface_pointer_type>(this->parent_class_type::get_pointer_()); }
// Not to be implemented
private: interface_cast_noaddref(class_type const& rhs); class_type const& operator =(class_type const& rhs);
// These are defined to placate Borland C/C++
void* operator new(cs_size_t /* si */) { return 0; } void operator delete(void* /* pv */) {} };
#endif /* STLSOFT_CF_EXCEPTION_SUPPORT */
/** \brief Interface cast for raw pointers that does add a net reference count
* * \ingroup group__library__conversion * * This class provides a cast between interface pointers, that adds a net reference count * * \param I The interface pointer type * \param X The exception type, defaulted to ignore_interface_cast_exception */ // [[synesis:class:cast: comstl::interface_cast_addref]]
template< ss_typename_param_k I , ss_typename_param_k X = ignore_interface_cast_exception > class interface_cast_addref : protected interface_cast_base<I, addref_release<I>, X> { private: // Member Types
typedef interface_cast_base<I, addref_release<I>, X> parent_class_type; public: /// The type of the current parameterisation
typedef interface_cast_addref<I, X> class_type; /// The interface pointer type
typedef ss_typename_type_k parent_class_type::interface_pointer_type interface_pointer_type;
public: // Construction
/// Constructor that attempts the speculative cast
#ifdef STLSOFT_CF_MEMBER_TEMPLATE_CTOR_SUPPORT
template <ss_typename_param_k J> ss_explicit_k interface_cast_addref(J j) : parent_class_type(j, parent_class_type::allowNull) {} #else /* ? STLSOFT_CF_MEMBER_TEMPLATE_CTOR_SUPPORT */
ss_explicit_k interface_cast_addref(LPUNKNOWN punk) : parent_class_type(punk, parent_class_type::allowNull) {} #endif /* STLSOFT_CF_MEMBER_TEMPLATE_CTOR_SUPPORT */
/// Constructor that directly casts (without calling QueryInterface())
ss_explicit_k interface_cast_addref(interface_pointer_type pi) : parent_class_type(pi, parent_class_type::allowNull) {}
#ifndef STLSOFT_DOCUMENTATION_SKIP_SECTION
~interface_cast_addref() stlsoft_throw_0() {} // We need to provide this to persuade VC6 to call the parent class dtor
#endif /* !STLSOFT_DOCUMENTATION_SKIP_SECTION */
// Accessors
public: /// A pointer to the acquired interface
operator interface_pointer_type () { return this->parent_class_type::get_pointer_(); }
// Not to be implemented
private: interface_cast_addref(class_type const& rhs); class_type const& operator =(class_type const& rhs);
// These are defined to placate Borland C/C++
void* operator new(cs_size_t /* si */) { return 0; } void operator delete(void* /* pv */) {} };
#ifndef STLSOFT_DOCUMENTATION_SKIP_SECTION
// [[synesis:class:cast: comstl::interface_cast_tester]]
template< ss_typename_param_k I > class interface_cast_tester : protected interface_cast_base<I, noaddref_release<I>, ignore_interface_cast_exception> { private: // Member Types
typedef interface_cast_base<I, noaddref_release<I>, ignore_interface_cast_exception> parent_class_type; public: /// The type of the current parameterisation
typedef interface_cast_tester<I> class_type; /// The interface pointer type
typedef ss_typename_type_k parent_class_type::interface_pointer_type interface_pointer_type; #ifdef STLSOFT_CF_TEMPLATE_PARTIAL_SPECIALISATION_SUPPORT
/// The interface type
typedef ss_typename_type_k parent_class_type::interface_type interface_type; typedef protect_refcount<interface_type>* protected_interface_pointer_type; #else /* ? STLSOFT_CF_TEMPLATE_PARTIAL_SPECIALISATION_SUPPORT */
typedef interface_pointer_type protected_interface_pointer_type; #endif /* STLSOFT_CF_TEMPLATE_PARTIAL_SPECIALISATION_SUPPORT */
public: // Construction
/// Constructor that attempts the speculative cast
#ifdef STLSOFT_CF_MEMBER_TEMPLATE_CTOR_SUPPORT
template <ss_typename_param_k J> ss_explicit_k interface_cast_tester(J &j) : parent_class_type(j, parent_class_type::allowNull) {} #else /* ? STLSOFT_CF_MEMBER_TEMPLATE_CTOR_SUPPORT */
ss_explicit_k interface_cast_tester(LPUNKNOWN punk) : parent_class_type(punk, parent_class_type::allowNull) {} #endif /* STLSOFT_CF_MEMBER_TEMPLATE_CTOR_SUPPORT */
/// Constructor that directly casts (without calling QueryInterface())
ss_explicit_k interface_cast_tester(interface_pointer_type pi) : parent_class_type(pi, parent_class_type::allowNull) {}
#ifndef STLSOFT_DOCUMENTATION_SKIP_SECTION
~interface_cast_tester() stlsoft_throw_0() {} // We need to provide this to persuade VC6 to call the parent class dtor
#endif /* !STLSOFT_DOCUMENTATION_SKIP_SECTION */
/// \name State
/// @{
private: STLSOFT_DEFINE_OPERATOR_BOOL_TYPES_T(class_type, operator_bool_generator_type, operator_bool_type); public: /// Represents whether the cast succeeded
///
/// \retval true The interface cast succeeded
/// \retval false The interface cast failed
operator operator_bool_type() const { return operator_bool_generator_type::translate(NULL != this->parent_class_type::get_pointer_()); } /// Represents whether the cast failed
///
/// \retval true The interface cast failed
/// \retval false The interface cast succeeded
cs_bool_t operator !() const { return NULL == this->parent_class_type::get_pointer_(); } /// @}
// Not to be implemented
private: interface_cast_tester(class_type const& rhs); class_type const& operator =(class_type const& rhs);
// These are defined to placate Borland C/C++
void* operator new(cs_size_t /* si */) { return 0; } void operator delete(void* /* pv */) {} };
#endif /* !STLSOFT_DOCUMENTATION_SKIP_SECTION */
/** \brief Determines whether an interface is available on an object
* * \ingroup group__library__conversion * * \param src The object whose capabilities will be tested. May be NULL * \code IStream* stm = . . .
if(comstl::interface_cast_test<IStorage*>(stm)) { printf("Object has IStorage interface\n"); } else { printf("Object does not have IStorage interface\n"); } \endcode */ template< ss_typename_param_k IDest , ss_typename_param_k ISrc > #if defined(STLSOFT_COMPILER_IS_MSVC) && \
_MSC_VER < 1300 // This workaround is required to stop the poor dear from instantiating
// interface_cast_tester on ISrc rather than IDest.
inline cs_bool_t interface_cast_test(ISrc* src, IDest* = NULL) #else /* ? compiler */
inline cs_bool_t interface_cast_test(ISrc* src) #endif /* compiler */
{ interface_cast_tester<IDest> b(src);
return !!b; }
/** \brief Determines whether an interface is available on an object
* * \ingroup group__library__conversion * \code stlsoft::ref_ptr<IStream> stm = . . .
if(comstl::interface_cast_test<IStorage>(stm)) { printf("Wrapper object has IStorage interface\n"); } else { printf("Wrapper object does not have IStorage interface\n"); } \endcode * * \param src wrapper instance holding the object whose capabilities * will be tested. May be empty. */ template< ss_typename_param_k IDest , ss_typename_param_k ISrc > #if defined(STLSOFT_COMPILER_IS_MSVC) && \
_MSC_VER < 1300 // This workaround is required to stop the poor dear from instantiating
// interface_cast_tester on ISrc rather than IDest.
inline cs_bool_t interface_cast_test(stlsoft_ns_qual(ref_ptr)<ISrc> &src, IDest* = NULL) #else /* ? compiler */
inline cs_bool_t interface_cast_test(stlsoft_ns_qual(ref_ptr)<ISrc> &src) #endif /* compiler */
{ return interface_cast_test<IDest*>(src.get()); }
#ifdef STLSOFT_CF_EXCEPTION_SUPPORT
/** \brief Casts a raw interface pointer to a wrapped instance.
* * \ingroup group__library__conversion * \code IStream* stm = . . .
try { stlsoft::ref_ptr<IStorage> stg = comstl::interface_cast<IStorage>(stm);
printf("Object has IStorage interface\n"); } catch(comstl::bad_interface_cast &) { printf("Object does not have IStorage interface\n"); } \endcode * * \note For technical reasons, the cast destination type differs from the * conventional behaviour. Rather than specifying the actual resultant * type, e.g. <code>stlsoft::ref_ptr<IStream></code>, just the destination * interface type must be specified, e.g. * <code>interface_cast<IStream></code>. * * \exception comstl::bad_interface_cast When compiling with exception - * detected when <code>STLSOFT_CF_EXCEPTION_SUPPORT</code> is defined - * this will throw an instance of comstl::bad_interface_cast if the * requested interface cannot be acquired. When compiling absent exception * support, this cast function is not defined; instead use * comstl::try_interface_cast. */ template< ss_typename_param_k IDest , ss_typename_param_k ISrc > inline stlsoft_ns_qual(ref_ptr)<IDest> interface_cast(ISrc* src) { interface_cast_addref<IDest*, throw_bad_interface_cast_exception> ptr(src); // This has to be separate, otherwise G++ has a spit
return stlsoft_ns_qual(ref_ptr)<IDest>(static_cast<IDest*>(ptr), false); }
/** \brief Casts between instances of wrapped instances
* * \ingroup group__library__conversion * \code stlsoft::ref_ptr<IStream> stm = . . .
try { stlsoft::ref_ptr<IStorage> stg = comstl::interface_cast<IStorage>(stm);
printf("Wrapper object has IStorage interface\n"); } catch(comstl::bad_interface_cast &) { printf("Wrapper object does not have IStorage interface\n"); } \endcode * * \note For technical reasons, the cast destination type differs from the * conventional behaviour. Rather than specifying the actual resultant * type, e.g. <code>stlsoft::ref_ptr<IStream></code>, just the destination * interface type must be specified, e.g. * <code>interface_cast<IStream></code>. * * \exception comstl::bad_interface_cast When compiling with exception - * detected when <code>STLSOFT_CF_EXCEPTION_SUPPORT</code> is defined - * this will throw an instance of comstl::bad_interface_cast if the * requested interface cannot be acquired. When compiling absent exception * support, this cast function is not defined; instead use * comstl::try_interface_cast. */ template< ss_typename_param_k IDest , ss_typename_param_k ISrc > inline stlsoft_ns_qual(ref_ptr)<IDest> interface_cast(stlsoft_ns_qual(ref_ptr)<ISrc> src) { return interface_cast<IDest>(src.get()); }
#endif /* STLSOFT_CF_EXCEPTION_SUPPORT */
/** \brief Attempts to cast a raw interface pointer to a wrapped instance.
* * \ingroup group__library__conversion * \code IStream* pstm = . . . stlsoft::ref_ptr<IStorage> stg = comstl::interface_cast<IStorage>(pstm);
if(!stg.empty()) { . . . // use stg->
} \endcode * * \note For technical reasons, the cast destination type differs from the * conventional behaviour. Rather than specifying the actual resultant * type, e.g. <code>stlsoft::ref_ptr<IStream></code>, just the destination * interface type must be specified, e.g. * <code>interface_cast<IStream></code>. * * \return */ template< ss_typename_param_k IDest , ss_typename_param_k ISrc > inline stlsoft_ns_qual(ref_ptr)<IDest> try_interface_cast(ISrc* src) { interface_cast_addref<IDest*> ptr(src); // This has to be separate, otherwise G++ has a spit
return stlsoft_ns_qual(ref_ptr)<IDest>(static_cast<IDest*>(ptr), false); }
/** \brief Attempts to cast between instances of wrapped instances
* * \ingroup group__library__conversion * * \note For technical reasons, the cast destination type differs from the * conventional behaviour. Rather than specifying the actual resultant * type, e.g. <code>stlsoft::ref_ptr<IStream></code>, just the destination * interface type must be specified, e.g. * <code>interface_cast<IStream></code>. */ template< ss_typename_param_k IDest , ss_typename_param_k ISrc > inline stlsoft_ns_qual(ref_ptr)<IDest> try_interface_cast(stlsoft_ns_qual(ref_ptr)<ISrc> src) { return try_interface_cast<IDest>(src.get()); }
/* /////////////////////////////////////////////////////////////////////////
* Shims */
#ifdef STLSOFT_CF_EXCEPTION_SUPPORT
# if !defined(STLSOFT_COMPILER_IS_COMO) && \
!defined(STLSOFT_COMPILER_IS_GCC)
/** \brief Attribute shim to retrieve the interface pointer of the given cast instance
* * \ingroup group__concept__shim__pointer_attribute__get_ptr * * \param p The cast instance */ template< ss_typename_param_k I , ss_typename_param_k X > inline I get_ptr(comstl_ns_qual(interface_cast_noaddref)<I, X> &p) { return p.operator -> (); } # endif /* compiler */
/** \brief Attribute shim to retrieve the interface pointer of the given cast instance
* * \ingroup group__concept__shim__pointer_attribute__get_ptr * * \param p The cast instance */ template< ss_typename_param_k I , ss_typename_param_k X > inline I get_ptr(comstl_ns_qual(interface_cast_noaddref)<I, X> const& p) { return p.operator -> (); }
#endif /* STLSOFT_CF_EXCEPTION_SUPPORT */
/** \brief Attribute shim to retrieve the interface pointer of the given cast instance
* * \ingroup group__concept__shim__pointer_attribute__get_ptr * * \param p The cast instance */ template< ss_typename_param_k I , ss_typename_param_k X > inline I get_ptr(comstl_ns_qual(interface_cast_addref)<I, X> &p) { return p; }
/** \brief Attribute shim to retrieve the interface pointer of the given cast instance
* * \ingroup group__concept__shim__pointer_attribute__get_ptr * * \param p The cast instance */ template< ss_typename_param_k I , ss_typename_param_k X > inline I const get_ptr(comstl_ns_qual(interface_cast_addref)<I, X> const& p) { return p; }
/* /////////////////////////////////////////////////////////////////////////
* Deprecated Shims */
#ifndef STLSOFT_DOCUMENTATION_SKIP_SECTION
# ifdef STLSOFT_CF_EXCEPTION_SUPPORT
template< ss_typename_param_k I , ss_typename_param_k X > inline cs_bool_t is_empty(comstl_ns_qual(interface_cast_noaddref)<I, X> const& p) { return NULL != get_ptr(p); }
# endif /* STLSOFT_CF_EXCEPTION_SUPPORT */
template< ss_typename_param_k I , ss_typename_param_k X > inline cs_bool_t is_empty(comstl_ns_qual(interface_cast_addref)<I, X> const& p) { return NULL != get_ptr(p); }
#endif /* !STLSOFT_DOCUMENTATION_SKIP_SECTION */
////////////////////////////////////////////////////////////////////////////
// Unit-testing
#ifdef STLSOFT_UNITTEST
# include "./unittest/interface_cast_unittest_.h"
#endif /* STLSOFT_UNITTEST */
/* ////////////////////////////////////////////////////////////////////// */
#ifndef _COMSTL_NO_NAMESPACE
# if defined(_STLSOFT_NO_NAMESPACE) || \
defined(STLSOFT_DOCUMENTATION_SKIP_SECTION) } // namespace comstl
# else
} // namespace comstl_project
} // namespace stlsoft
# endif /* _STLSOFT_NO_NAMESPACE */
#endif /* !_COMSTL_NO_NAMESPACE */
/* /////////////////////////////////////////////////////////////////////////
* Namespace * * The string access shims exist either in the stlsoft namespace, or in the * global namespace. This is required by the lookup rules. * */
#ifndef _COMSTL_NO_NAMESPACE
# if !defined(_STLSOFT_NO_NAMESPACE) && \
!defined(STLSOFT_DOCUMENTATION_SKIP_SECTION) namespace stlsoft { # else /* ? _STLSOFT_NO_NAMESPACE */
/* There is no stlsoft namespace, so must define in the global namespace */ # endif /* !_STLSOFT_NO_NAMESPACE */
using ::comstl::get_ptr;
#ifndef STLSOFT_DOCUMENTATION_SKIP_SECTION
using ::comstl::is_empty;
#endif /* !STLSOFT_DOCUMENTATION_SKIP_SECTION */
# if !defined(_STLSOFT_NO_NAMESPACE) && \
!defined(STLSOFT_DOCUMENTATION_SKIP_SECTION) } // namespace stlsoft
# else /* ? _STLSOFT_NO_NAMESPACE */
/* There is no stlsoft namespace, so must define in the global namespace */ # endif /* !_STLSOFT_NO_NAMESPACE */
#endif /* !_COMSTL_NO_NAMESPACE */
/* ////////////////////////////////////////////////////////////////////// */
#endif /* !COMSTL_INCL_COMSTL_CONVERSION_HPP_INTERFACE_CAST */
/* ///////////////////////////// end of file //////////////////////////// */
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