X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/ae3c17b4013e80b99976c750c19fca47729517f6..36a0190ebd5bd9a7302f60f6dcd608b80574e21c:/interface/wx/scopeguard.h diff --git a/interface/wx/scopeguard.h b/interface/wx/scopeguard.h index e8c88a7989..8da75963a4 100644 --- a/interface/wx/scopeguard.h +++ b/interface/wx/scopeguard.h @@ -2,17 +2,66 @@ // Name: scopeguard.h // Purpose: interface of global functions // Author: wxWidgets team -// RCS-ID: $Id$ -// Licence: wxWindows license +// Licence: wxWindows licence ///////////////////////////////////////////////////////////////////////////// -/** @ingroup group_funcmacro_misc */ +/** + @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 */ //@{ /** - This macro ensures that the global @a function with 0, 1, 2 or more - parameters (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: + 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); @@ -26,38 +75,44 @@ @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) //@} -/** @ingroup group_funcmacro_misc */ +/** @addtogroup group_funcmacro_misc */ //@{ /** - This family of macros is similar to wxON_BLOCK_EXIT0(), but calls a method + 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) //@} -/** @ingroup group_funcmacro_misc */ +/** @addtogroup group_funcmacro_misc */ //@{ /** - This family of macros is similar to wxON_BLOCK_OBJ0(), but calls a method + 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) //@} -/** @ingroup group_funcmacro_misc */ +/** @addtogroup group_funcmacro_misc */ //@{ /** This macro sets a variable to the specified value on scope exit. @@ -75,6 +130,9 @@ } @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}