///////////////////////////////////////////////////////////////////////////// // Name: scopeguard.h // Purpose: interface of global functions // Author: wxWidgets team // Licence: wxWindows licence ///////////////////////////////////////////////////////////////////////////// /** @class wxScopeGuard Scope guard is an object which allows executing an action on scope exit. The objects of this class must be constructed using wxMakeGuard() function. @nolibrary @category{misc} */ class wxScopeGuard { public: /** Call this method to dismiss the execution of the action on scope exit. A typical example: @code Update1(); // ensure that changes done so far are rolled back if the next // operation throws wxScopeGuard guard = wxMakeGuard(RollBack); Update2(); // it didn't throw so commit the changes, i.e. avoid rolling back guard.Dismiss(); @endcode */ void Dismiss(); }; /** @addtogroup group_funcmacro_misc */ ///@{ /** Returns a scope guard object which will call the specified function with the given parameters on scope exit. This function is overloaded to take several parameters up to some implementation-defined (but relatively low) limit. The @a func should be a functor taking parameters of the types P1, ..., PN, i.e. the expression @c func(p1, ..., pN) should be valid. */ template wxScopeGuard wxMakeGuard(F func, P1 p1, ..., PN pN); ///@} /** @addtogroup group_funcmacro_misc */ ///@{ /** Ensure that the global @a function with a few (up to some implementation-defined limit) is executed on scope exit, whether due to a normal function return or because an exception has been thrown. A typical example of its usage: @code void *buf = malloc(size); wxON_BLOCK_EXIT1(free, buf); @endcode Please see the original article by Andrei Alexandrescu and Petru Marginean published in December 2000 issue of C/C++ Users Journal for more details. @see wxON_BLOCK_EXIT_OBJ0() @header{wx/scopeguard.h} */ #define wxON_BLOCK_EXIT(function, ...) #define wxON_BLOCK_EXIT0(function) #define wxON_BLOCK_EXIT1(function, p1) #define wxON_BLOCK_EXIT2(function, p1, p2) #define wxON_BLOCK_EXIT3(function, p1, p2, p3) ///@} /** @addtogroup group_funcmacro_misc */ ///@{ /** This family of macros is similar to wxON_BLOCK_EXIT(), but calls a method of the given object instead of a free function. @header{wx/scopeguard.h} */ #define wxON_BLOCK_EXIT_OBJ(object, method, ...) #define wxON_BLOCK_EXIT_OBJ0(object, method) #define wxON_BLOCK_EXIT_OBJ1(object, method, p1) #define wxON_BLOCK_EXIT_OBJ2(object, method, p1, p2) #define wxON_BLOCK_EXIT_OBJ3(object, method, p1, p2, p3) ///@} /** @addtogroup group_funcmacro_misc */ ///@{ /** This family of macros is similar to wxON_BLOCK_OBJ(), but calls a method of @c this object instead of a method of the specified object. @header{wx/scopeguard.h} */ #define wxON_BLOCK_EXIT_THIS(method, ...) #define wxON_BLOCK_EXIT_THIS0(method) #define wxON_BLOCK_EXIT_THIS1(method, p1) #define wxON_BLOCK_EXIT_THIS2(method, p1, p2) #define wxON_BLOCK_EXIT_THIS3(method, p1, p2, p3) ///@} /** @addtogroup group_funcmacro_misc */ ///@{ /** This macro sets a variable to the specified value on scope exit. Example of usage: @code void foo() { bool isDoingSomething = true; { wxON_BLOCK_EXIT_SET(isDoingSomething, false); ... do something ... } ... isDoingSomething is false now ... } @endcode Notice that @a value is copied, i.e. stored by value, so it can be a temporary object returned by a function call, for example. @see wxON_BLOCK_EXIT_OBJ0(), wxON_BLOCK_EXIT_NULL() @header{wx/scopeguard.h} */ #define wxON_BLOCK_EXIT_SET(var, value) /** This macro sets the pointer passed to it as argument to NULL on scope exit. It must be used instead of wxON_BLOCK_EXIT_SET() when the value being set is @c NULL. @header{wx/scopeguard.h} */ #define wxON_BLOCK_EXIT_NULL(ptr) ///@}