The following program won't compile if I uncomment the if statement:

void main()
{
    Variant v = complex(1.0, 1.0);

//    if (v.peek!(Complex)) {
//        writeln("Complex");
//    }
    writeln(v);
}

I get the same error with v.peek!(complex), which is:

Error: template instance peek!(Complex) does not match template declaration peek(T)()

The variant can clearly hold a complex value. Someone please tell me - what am I doing wrong in the peek call?

On Saturday, 22 February 2020 at 18:00:16 UTC, Vinay Sajip wrote:
> The following program won't compile if I uncomment the if statement:
>
> void main()
> {
>     Variant v = complex(1.0, 1.0);
>
> //    if (v.peek!(Complex)) {
> //        writeln("Complex");
> //    }
>     writeln(v);
> }
>
> I get the same error with v.peek!(complex), which is:
>
> Error: template instance peek!(Complex) does not match template declaration peek(T)()
>
> The variant can clearly hold a complex value. Someone please tell me - what am I doing wrong in the peek call?

The type in v isn't Complex, it's Complex!double.

This will work the way you want:
```
void main()
{
    Variant v = complex(1.0, 1.0);

    if (v.peek!(Complex!double))
    {
        writeln("Complex");
    }

    writeln(v);
}
```

On Saturday, 22 February 2020 at 18:32:06 UTC, nullptr wrote:
>
> The type in v isn't Complex, it's Complex!double.
>

Ah, great. Thanks! Missed that.