Re: Debug help - delegate from dlang Tour

[evilrat via Digitalmars-d-learn]

On Monday, 8 September 2025 at 14:32:32 UTC, Brother Bill wrote:
https://tour.dlang.org/tour/en/basics/delegates
This is so simple.  What is D complaining about?
Should this also work with a Template, as shown?

```
import std.stdio;

void main()
{
        // auto add(T)(T lhs, T rhs)
        // {
        //      return lhs + rhs;
        // }

        int add(int lhs, int rhs) {
                return lhs + rhs;
        }

        int doSomething(int function(int, int) doer)
        {
                // call passed function
                return doer(5, 6);
        }

        doSomething(&add);

}

```

Console output:
```
c:\dev\D\D_templates_tutorial\toy1\source\app.d(20): Error: 
function `doSomething` is not callable using argument types 
`(int delegate(int lhs, int rhs) pure nothrow @nogc @safe)`
    doSomething(&add);
               ^
c:\dev\D\D_templates_tutorial\toy1\source\app.d(20):        
cannot pass argument `&add` of type `int delegate(int lhs, int 
rhs) pure nothrow @nogc @safe` to parameter `int function(int, 
int) doer`
c:\dev\D\D_templates_tutorial\toy1\source\app.d(14):        
`app.main.doSomething(int function(int, int) doer)` declared 
here
    int doSomething(int function(int, int) doer)
        ^
```

probably because you have declared nested function `add` inside 
`main`, this creates a delegate closure capturing `main` scope, 
if you don't want that just mark `add` static.