add 3 parameter scope guard; improve its documentation

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@56194 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/scopeguard.h

@@ -6,13 +6,58 @@
 // Licence:     wxWindows license
 /////////////////////////////////////////////////////////////////////////////
 
+/**
+    Scope guard is an object which allows executing an action on scope exit.
+
+    The objects of this class must be constructed using wxMakeGuard() function.
+ */
+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();
+};
+
 /** @ingroup 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 <typename F, typename P1, ..., typename PN>
+wxScopeGuard wxMakeGuard(F func, P1 p1, ..., PN pN);
+
+//@}
+
+/** @ingroup 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);
@@ -26,35 +71,41 @@
 
     @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 */
 //@{
 /**
-    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 */
 //@{
 /**
-    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 */