Re: Alias type with different initialiser.

[Bastiaan Veelo via Digitalmars-d-learn]

On Monday, 13 February 2017 at 16:40:02 UTC, Daniel Kozak wrote:
https://dlang.org/phobos/std_typecons.html#.Typedef

Thanks for the pointers. Both Typedef and Proxy create types that 
don't mix with the base type, which I want to the contrary. So I 
guess I'll go with

struct Initial(T, T val)
{
    private T _payload = val;
    alias _payload this;

    static Initial opCall(T v)
    {
        Initial s;
        s._payload = v;
        return s;
    }

    static T init()
    {
        return val;
    }
}

unittest
{
    alias Initial!(int, 1) int1;
    int1 i;
    assert(i == 1);
    int1 ii = 2;
    assert(ii == 2);
    assert(ii.init == 1);
    assert(int1.init == 1);

    void f(int val)
    {
        assert(val == 1);
    }
    f(i);

    int i0;
    assert(i0 == 0);
    i = i0;
    assert(i == 0);
    assert(i.init == 1);
    i0 = ii;
    assert(i0 == 2);
    assert(i0.init == 0);
}