Re: Option types and pattern matching.

[Kagamin via Digitalmars-d]

On Monday, 26 October 2015 at 16:42:27 UTC, TheFlyingFiddle wrote:

If you instead use pattern matching as in your example you have much better context information that can actually help you do something in the case a value is not there.

Probably possible:

Some!T get(T)(Option!T item) {
    Some!T r;
    //Static guarantee of handling value not present
    item match {
        None() => {
            throw new Exception("empty!");
        }
        Some(t) => {
            r=t;
        }
    }

    return r;
}

Then:
Option!File file;
Some!File s = file.get();