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//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift open source project
//
// Copyright (c) 2020 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 the list of Swift project authors
//
//===----------------------------------------------------------------------===//
extension Dictionary {
@inlinable
@discardableResult
public mutating func memoize(key: Key, body: () throws -> Value) rethrows -> Value {
if let value = self[key] {
return value
}
let value = try body()
self[key] = value
return value
}
}
extension Dictionary {
public init<S>(throwingUniqueKeysWithValues keysAndValues: S) throws where S: Sequence, S.Element == (Key, Value) {
self.init()
for pair in keysAndValues {
guard !self.keys.contains(pair.0) else {
throw StringError("duplicate key found: '\(pair.0)'")
}
self[pair.0] = pair.1
}
}
}
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