typeof(func!0) != typeof(func!0())

[JG]

On Monday, 22 August 2022 at 04:39:18 UTC, Andrey Zherikov wrote:
> I have this simple code:
> ```d
> struct U
> {
>     auto ref func(int i)() { return this; }
> }
>
> void main()
> {
>     {
>         alias type = typeof(U().func!0);
>         pragma(msg, type);  		// pure nothrow @nogc ref @safe 
> U() return
>         pragma(msg, is(type : U));  // false
>
>         auto u = U().func!0;
>         pragma(msg, typeof(u));		// U
>     }
>     {
>         alias type = typeof(U().func!0());
>         pragma(msg, type);  		// U
>         pragma(msg, is(type : U));  // true
>
>         auto u = U().func!0();
>         pragma(msg, typeof(u));		// U
>     }
> }
> ```
> Why does `typeof(U().func!0)` != `U`? How can I check that the 
> returned value has type `U` in this case?

Why not just change to:
alias type = typeof(U().func!0());