Operator '&' cannot be applied to operands of type 'T' and 'T'

Question

My application defines several enums that include the [Flags] attribute.

I wanted to write a small utility method to check if a flag was set for any of those enums and I came up with the following.

protected static bool IsFlagSet<T>(ref T value, ref T flags)
{
    return ((value & flags) == flags);
}

But this gives me the error "Operator '&' cannot be applied to operands of type 'T' and 'T'".

Can this be made to work?

Answer 1

& is an operator on a class type. Which means that the class T has to have a method that overloads the operator &.

.Net can't expect that every class will have it. So it fails.

What you can do, is make a base class, that declares the operator overload as a method.

Then use Constraints to declare that T uses that base class:

protected static bool IsFlagSet<T> where T: BaseclassWithAnd (ref T value, ref T flags)
{
    return ((value & flags) == flags);
}