如何在 Nullable 中使用运算符“is”

Question

I want to use the "is" operator to unwrap Nullable. Something like:

if(nullable is not null notNullValue)
    notNullValue.ToString();

The workaround I'm using:

if(value is SomeType notNullValue)
    notNullValue.ToString();

Using an additional variable in this case is ugly:

class Sample {
    public Enum? Get() {...}
}
data.Select(x => (Sample)x)
    .Where(x => x.Get() is Enum enumValue ? StrictCheck(enumValue) : false)
    .Select(...)
    .ToArray();

Is there no way not to re-write the type?

Answer 1

Seems like the best solution:

    public static bool TryGetValue<T>(this T? nullable, out T value) where T : struct {
        if (nullable is T notNullValue) {
            value = notNullValue;
            return true;
        }
        value = default(T);
        return false;
    }