Created
January 9, 2018 11:05
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[SWIFT 4.0] fatalError with clean way from https://github.com/JohnSundell/Require/blob/master/Sources/Require.swift
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| /** | |
| * Require | |
| * Copyright (c) John Sundell 2017 | |
| * Licensed under the MIT license. See LICENSE file. | |
| */ | |
| import Foundation | |
| public extension Optional { | |
| /** | |
| * Require this optional to contain a non-nil value | |
| * | |
| * This method will either return the value that this optional contains, or trigger | |
| * a `preconditionFailure` with an error message containing debug information. | |
| * | |
| * - parameter hint: Optionally pass a hint that will get included in any error | |
| * message generated in case nil was found. | |
| * | |
| * - return: The value this optional contains. | |
| */ | |
| func require(hint hintExpression: @autoclosure () -> String? = nil, | |
| file: StaticString = #file, | |
| line: UInt = #line) -> Wrapped { | |
| guard let unwrapped = self else { | |
| var message = "Required value was nil in \(file), at line \(line)" | |
| if let hint = hintExpression() { | |
| message.append(". Debugging hint: \(hint)") | |
| } | |
| #if !os(Linux) | |
| let exception = NSException( | |
| name: .invalidArgumentException, | |
| reason: message, | |
| userInfo: nil | |
| ) | |
| exception.raise() | |
| #endif | |
| preconditionFailure(message) | |
| } | |
| return unwrapped | |
| } | |
| } |
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