Re: Querying parameter passing semantics for `auto ref const` variables

[Nordlöw via Digitalmars-d-learn]

On Sunday, 15 January 2017 at 17:00:41 UTC, kinke wrote:

On Sunday, 15 January 2017 at 14:33:25 UTC, Nordlöw wrote:

A call to `isRef!T` inside the function `f` is always `false` for `l-value` and `r-value` passing.

According to https://dlang.org/spec/template.html#auto-ref-parameters, it should be `__traits(isRef, x)`.

This

    struct S { int x, y; }
    void f()(auto ref const S s)
    {
        pragma(msg, "type:", typeof(s), " isRef:", isRef!s);
    }
    f(S.init);
    S s;
    f(s);

prints

    type:const(S) isRef:false
    type:const(S) isRef:true

I made the mistake of incorrectly using

    isRef!S

when I should have used

    isRef!s

Thanks!