Weird template error message

[Paul Backus]

On Friday, 15 May 2020 at 21:40:20 UTC, NaN wrote:
> Stripped down example...
>
> module test;
>
> import std.traits;
>
> auto offsetBy(T,F)(T path, F x, F y)
> {
>     alias PathFloat = TemplateArgsOf!T[0];
>
>     struct Offseter(Q)
>     {
>         Q path;
>         PathFloat x;
>         PathFloat y;
>     }
>
>     return Offseter(path, cast(PathFloat) x, cast(PathFloat) y);

This line is the problem. Template argument deduction does not 
work for constructors; you have to write `Offsetter!T(...)`.