Re: Subrange type

[Paul Backus via Digitalmars-d-learn]

On Monday, 27 January 2020 at 20:06:14 UTC, Herbert wrote:

How can I create a subrange type, for example ushort DiceValue {1 .. 6}?

Probably the closest you can get is a struct with an invariant:

import std.traits: isOrderingComparable;

struct Subrange(T, T min, T max)
    if (isOrderingComparable!T)
{
    private T value_ = min;
    invariant(min <= value && value <= max);

    this(T t) { value_ = t; }

    T value() { return value_; }
    alias value this;

    ref Subrage opAssign(T t) { value_ = t; return this; }
}