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/*
This source file is part of the Swift.org open source project
Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
Licensed under Apache License v2.0 with Runtime Library Exception
See http://swift.org/LICENSE.txt for license information
See http://swift.org/CONTRIBUTORS.txt for Swift project authors
*/
extension Collection {
/// Returns the only element of the collection or nil.
public var spm_only: Element? {
return count == 1 ? self[startIndex] : nil
}
/// Prints the element of array to standard output stream.
///
/// This method should be used for debugging only.
public func spm_dump() {
for element in self {
print(element)
}
}
}
extension Collection where Element: Hashable {
/// Returns a new list of element removing duplicate elements.
///
/// Note: The order of elements is preseved.
/// Complexity: O(n)
public func spm_uniqueElements() -> [Element] {
var set = Set<Element>()
var result = [Element]()
for element in self {
if set.insert(element).inserted {
result.append(element)
}
}
return result
}
}
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