//  *******************************************************************************
//  The MIT License (MIT)
//
//  Copyright (c) 2017 Jean-David Gadina - www.xs-labs.com
//
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/// Protocol for `AtomicKit` thread-safe wrapper objects around a value/type.
public protocol ThreadSafeValueWrapper {

    associatedtype ValueType

    /// Required initializer.
    ///
    /// Initializes a thread-safe wrapper object with a default value.
    ///
    /// - Parameter value: The default value for the wrapped type.
    init(value: ValueType)

    /// Atomically gets the value of the wrapped type.
    ///
    /// - Returns: The actual value of the wrapped type.
    func get() -> ValueType

    /// Atomically sets the value of the wrapped type.
    ///
    /// - Parameter value: The value to set for the wrapped type.
    func set(_ value: ValueType)

    /// Atomically executes a custom closure, receiving the value of the wrapped type.
    ///
    /// The passed closure is guaranteed to be executed atomically, in respect of the current value of the
    /// wrapped type.
    ///
    /// - Parameter closure: The closure to execute.
    func execute(closure: (ValueType) -> Void)

    /// Atomically executes a custom closure, receiving the value of the wrapped type.
    ///
    /// The passed closure is guaranteed to be executed atomically, in respect of the current value of the
    /// wrapped type.
    ///
    /// - Parameter closure: The closure to execute.
    ///
    /// - Returns: The closure's return value.
    func execute<R>(closure: (ValueType) -> R) -> R

}
