Index: src/OFArray.h
==================================================================
--- src/OFArray.h
+++ src/OFArray.h
@@ -18,10 +18,11 @@
 @class OFDataArray;
 @class OFString;
 
 #ifdef OF_HAVE_BLOCKS
 typedef void (^of_array_enumeration_block_t)(id obj, size_t idx, BOOL *stop);
+typedef BOOL (^of_array_filter_block_t)(id odj, size_t idx);
 #endif
 
 /**
  * \brief A class for storing objects in an array.
  */
@@ -203,10 +204,20 @@
  * Executes a block for each object.
  *
  * \param block The block to execute for each object
  */
 - (void)enumerateObjectsUsingBlock: (of_array_enumeration_block_t)block;
+
+/**
+ * Returns a new array, only containing the objects for which the block returns
+ * YES.
+ *
+ * \param block A block which determines if the object should be in the new
+ *		array
+ * \return A new, autoreleased OFArray
+ */
+- (OFArray*)filteredArrayUsingBlock: (of_array_filter_block_t)block;
 #endif
 @end
 
 @interface OFArrayEnumerator: OFEnumerator
 {

Index: src/OFArray.m
==================================================================
--- src/OFArray.m
+++ src/OFArray.m
@@ -400,10 +400,31 @@
 	BOOL stop = NO;
 
 	for (i = 0; i < count && !stop; i++)
 		block(objs[i], i, &stop);
 }
+
+- (OFArray*)filteredArrayUsingBlock: (of_array_filter_block_t)block
+{
+	size_t count = [array count];
+	id *tmp = [self allocMemoryForNItems: count
+				    withSize: sizeof(id)];
+
+	@try {
+		id *objs = [array cArray];
+		size_t i, j = 0;
+
+		for (i = 0; i < count; i++)
+			if (block(objs[i], i))
+				tmp[j++] = objs[i];
+
+		return [OFArray arrayWithCArray: tmp
+					 length: j];
+	} @finally {
+		[self freeMemory: tmp];
+	}
+}
 #endif
 
 - (void)dealloc
 {
 	id *objs = [array cArray];

Index: src/OFDictionary.h
==================================================================
--- src/OFDictionary.h
+++ src/OFDictionary.h
@@ -17,10 +17,11 @@
 
 @class OFArray;
 
 #ifdef OF_HAVE_BLOCKS
 typedef void (^of_dictionary_enumeration_block_t)(id key, id obj, BOOL *stop);
+typedef BOOL (^of_dictionary_filter_block_t)(id key, id obj);
 #endif
 
 struct of_dictionary_bucket
 {
 	id <OFCopying> key;
@@ -162,10 +163,21 @@
  *
  * \param block The block to execute for each key / object pair.
  */
 - (void)enumerateKeysAndObjectsUsingBlock:
     (of_dictionary_enumeration_block_t)block;
+
+/**
+ * Returns a new dictionary, only containing the objects for which the block
+ * returns YES.
+ *
+ * \param block A block which determines if the object should be in the new
+ *		dictionary
+ * \return A new, autoreleased OFDictionary
+ */
+- (OFDictionary*)filteredDictionaryUsingBlock:
+    (of_dictionary_filter_block_t)block;
 #endif
 @end
 
 @interface OFDictionaryEnumerator: OFEnumerator
 {

Index: src/OFDictionary.m
==================================================================
--- src/OFDictionary.m
+++ src/OFDictionary.m
@@ -572,10 +572,25 @@
 
 	for (i = 0; i < size && !stop; i++)
 		if (data[i] != NULL && data[i] != DELETED)
 			block(data[i]->key, data[i]->object, &stop);
 }
+
+- (OFDictionary*)filteredDictionaryUsingBlock:
+    (of_dictionary_filter_block_t)block
+{
+	OFMutableDictionary *dict = [OFMutableDictionary dictionary];
+	size_t i;
+
+	for (i = 0; i < size; i++)
+		if (data[i] != NULL && data[i] != DELETED)
+			if (block(data[i]->key, data[i]->object))
+				[dict setObject: data[i]->object
+					 forKey: data[i]->key];
+
+	return dict;
+}
 #endif
 
 - (void)dealloc
 {
 	uint32_t i;

Index: tests/OFArrayTests.m
==================================================================
--- tests/OFArrayTests.m
+++ tests/OFArrayTests.m
@@ -246,12 +246,16 @@
 		case 1:
 			return @"bar";
 		}
 
 		return nil;
-	    }]) && [[m[0] objectAtIndex: 0] isEqual: @"foo"] &&
-	    [[m[0] objectAtIndex: 1] isEqual: @"bar"])
+		}]) && [[m[0] description] isEqual: @"(foo, bar)"])
+
+	TEST(@"-[filteredArrayUsingBlock:]",
+	   [[[m[0] filteredArrayUsingBlock: ^ BOOL (id obj, size_t idx) {
+		return ([obj isEqual: @"foo"] ? YES : NO);
+	    }] description] isEqual: @"(foo)"])
 #endif
 
 	[pool drain];
 }
 @end

Index: tests/OFDictionaryTests.m
==================================================================
--- tests/OFDictionaryTests.m
+++ tests/OFDictionaryTests.m
@@ -141,10 +141,15 @@
 			return @"value_2";
 
 		return nil;
 	    }]) && [[dict objectForKey: keys[0]] isEqual: @"value_1"] &&
 	    [[dict objectForKey: keys[1]] isEqual: @"value_2"])
+
+	TEST(@"-[filteredDictionaryUsingBlock:]",
+	    [[[dict filteredDictionaryUsingBlock: ^ BOOL (id key, id obj) {
+		return ([key isEqual: keys[0]] ?  YES : NO);
+	    }] description] isEqual: @"{key1 = value_1}"])
 #endif
 
 	TEST(@"-[count]", [dict count] == 2)
 
 	TEST(@"+[dictionaryWithKeysAndObjects:]",