Files
sourcekit-lsp/Sources/SwiftExtensions/Collection+Only.swift
Alex Hoppen b479b2e874 Create a SwiftExtensions module
This allows us to share common Swift utility functions between SourceKit-LSP and LSPLogging.
2024-06-04 07:06:44 -07:00

23 lines
777 B
Swift

//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2023 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
public extension Collection {
/// If the collection contains a single element, return it, otherwise `nil`.
var only: Element? {
if !isEmpty && index(after: startIndex) == endIndex {
return self.first!
} else {
return nil
}
}
}