Detect the presence of libdispatch and, if available, use it for collection

enumeration methods that take blocks as arguments. This allows us to implement
the NSEnumerationConcurrent option of those methods with minimal effort.

The searching methods on NSIndexSet and all the sorting methods are still
missing.



git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@35010 72102866-910b-0410-8b05-ffd578937521

Headers/Foundation/NSIndexSet.h

@@ -3,19 +3,19 @@
 
    Written by:  Richard Frith-Macdonald <rfm@gnu.org>
    Created: Feb 2004
-   
+
    This file is part of the GNUstep Base Library.
 
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.
-   
+
    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.
-   
+
    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free
    Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
@@ -23,11 +23,12 @@
 
    AutogsdocSource: NSIndexSet.m
 
-   */ 
+   */
 
 #ifndef _NSIndexSet_h_GNUSTEP_BASE_INCLUDE
 #define _NSIndexSet_h_GNUSTEP_BASE_INCLUDE
 #import	<GNUstepBase/GSVersionMacros.h>
+#import <GNUstepBase/GSBlocks.h>
 
 #if OS_API_VERSION(GS_API_MACOSX, GS_API_LATEST)
 
@@ -89,13 +90,28 @@ extern "C" {
  */
 - (NSUInteger) count;
 
-#if OS_API_VERSION(100500,GS_API_LATEST) 
+#if OS_API_VERSION(100500,GS_API_LATEST)
 /** Not implemented
  * Returns the number of indexes set within the specified range.
  */
 - (NSUInteger) countOfIndexesInRange: (NSRange)range;
 #endif
 
+#if OS_API_VERSION(100600,GS_API_LATEST)
+DEFINE_BLOCK_TYPE(GSIndexSetEnumerationBlock, void, NSUInteger, BOOL*);
+- (void)enumerateIndexesInRange: (NSRange)range
+                        options: (NSEnumerationOptions)opts
+		     usingBlock: (GSIndexSetEnumerationBlock)aBlock;
+/**
+ * Enumerate all indices in the set by applying a block to them.
+ */
+- (void)enumerateIndexesUsingBlock: (GSIndexSetEnumerationBlock)aBlock;
+
+- (void)enumerateIndexesWithOptions: (NSEnumerationOptions)opts
+		         usingBlock: (GSIndexSetEnumerationBlock)aBlock;
+
+#endif
+
 /**
  * Returns the first index value in the receiver or NSNotFound if the
  * receiver is empty.
@@ -222,7 +238,7 @@ extern "C" {
  * anIndex.
  */
 - (void) shiftIndexesStartingAtIndex: (NSUInteger)anIndex
-				  by: (NSInteger)amount;   
+				  by: (NSInteger)amount;
 
 @end