Implement CompareAndSwap for bool

Question

In .NET framework, atomic operation CompareAndExchange is only defined for int, long, double and reference type. But I need CompareAndExchange for bool type. How can I implement CompareAndSwap for bool?

Answer 1

You can define wrapper boolean values, and use the CompareExchange overload for T where T : class, like this:

private static object TrueObj = true;
private static object FalseObj = false;
...
object val = TrueObj;
object result = Interlocked.CompareExchange(ref val, TrueObj, FalseObj);
if (val == FalseObj) { // Alternatively you could use if (!(bool)val) ...
    ...
}

Answer 2

An alternative to dablinkenlight's approach would be to use the Int32 overload where 0 is false and any non-zero value is true.