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EnumAssociable.swift
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EnumAssociable.swift
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//
// EnumAssociable.swift
// SwiftFormat
//
// Created by Vincent Bernier on 13-02-18.
// Copyright © 2018 Nick Lockwood.
//
// Distributed under the permissive MIT license
// Get the latest version from here:
//
// https://github.com/nicklockwood/SwiftFormat
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//
import Foundation
protocol EnumAssociable {}
extension EnumAssociable {
private var _associatedValue: Any? {
let mirror = Mirror(reflecting: self)
precondition(mirror.displayStyle == Mirror.DisplayStyle.enum, "Can only be apply to an Enum")
let optionalValue = mirror.children.first?.value
if let value = optionalValue {
let description = "\(value)"
precondition(!description.contains("->") && !description.contains("(Function)"),
"Doesn't work when associated value is a closure")
}
return optionalValue
}
func associatedValue<T: _Optional>() -> T {
guard let value = _associatedValue else {
return T._none
}
return value as! T
}
func associatedValue<T>() -> T {
_associatedValue as! T
}
}
protocol _Optional {
static var _none: Self { get }
}
extension Optional: _Optional {
static var _none: Optional { none }
}