/*
 *
 * Copyright 2015, Google Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#import <Foundation/Foundation.h>

@interface NSEnumerator (GRXUtil)

/**
 * Returns a NSEnumerator instance that iterates through the elements of the passed container that
 * supports fast enumeration. Note that this negates the speed benefits of fast enumeration over
 * NSEnumerator. It's only intended for the rare cases when one needs the latter and only has the
 * former, e.g. for iteration that needs to be paused and resumed later.
 */
+ (NSEnumerator *)grx_enumeratorWithContainer:(id<NSFastEnumeration>)container;

/**
 * Returns a NSEnumerator instance that provides a single object before finishing. The value is then
 * released.
 */
+ (NSEnumerator *)grx_enumeratorWithSingleValue:(id)value;

/**
 * Returns a NSEnumerator instance that delegates the invocations of nextObject to the passed block.
 * When the block first returns nil, it is released.
 */
+ (NSEnumerator *)grx_enumeratorWithValueSupplier:(id (^)())block;
@end