template struct question

[bkoie]

On Wednesday, 12 February 2025 at 20:55:14 UTC, WhatMeWorry wrote:
> ```
> void main()
> {
>
> struct HexBoard(F,I)
> {
>     this(F d, I r, I c) {}
>     //void displayHexBoard(HexBoard!(F,I) h) {}  // this 
> compiles fine!
> }
>
> void displayHexBoard(HexBoard!(F,I) h) {}  // error undefined 
> identifier F and I
>
>
> auto h1 = HexBoard!(float,uint)(.25, 3, 7);
> auto h2 = HexBoard!(double,int)(.3, 5, 5);
>
> }
>
>
> Is there any clever way to move the method outside of a 
> templated block structure?  Or is this as good as it gets.
>
> I tried
> // Explicit instantiation for 'int' type
> //int add!(int, int);
> void displayHexBoardData(HexBoard2!(float,uint) h);  // 
> declaration
>
> but that just returns
> Error: declaration `displayHexBoard` is already defined
> onlineapp.d(10):        `function` `displayHexBoard` is defined 
> here

```d
import std.stdio;

struct Foo(T, L) { T t; L l; }
void display(T, L)(Foo!(T, L) f) { f.writeln; }

alias FooIntD = Foo!(int, double);
void main() { auto f = FooIntD(10, 20.3); f.display; }
```