Re: taggedalgebraic 0.11.0 adds TaggedUnion

[Sönke Ludwig via Digitalmars-d-announce]

Am 23.02.2019 um 14:18 schrieb Sönke Ludwig:

Am 23.02.2019 um 09:51 schrieb Jacob Carlborg:

(...)

Why not using property syntax, i.e. `val.height = 10`?

The main reason is to distinguish the act of setting a new value from the one of modifying an existing value. In the former case it is okay if the currently stored kind/type differs, but in the latter case that would be a programming error.

To follow up on that, in the example above it would be possible to do this:

    val.setHeight(10);
    val.heightValue++;
    assert(val.heightValue == 11);

    //val.captionValue = "foo"; // throws an AssertError

Then there is also a generic variant of the above:

    val.set!(Value.Kind.height)(10);
    val.value!(Value.Kind.height)++;
    val.value!int++;