On Monday, 8 September 2025 at 14:42:01 UTC, evilrat wrote:
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.
Marking add static works.
Still don't understand why this doesn't work.
```
import std.stdio;
void main()
{
foo();
}
void foo() {
int addMyInts(int lhs, int rhs) {
return lhs + rhs;
}
int doSomething(int function(int, int) doer)
{
// call passed function
return doer(5, 6);
}
doSomething(&addMyInts);
}
```
Console output
```
c:\dev\D\D_templates_tutorial\toy1\source\app.d(19): Error:
function `doSomething` is not callable using argument types `(int
delegate(int lhs, int rhs) pure nothrow @nogc @safe)`
doSomething(&addMyInts);
^
c:\dev\D\D_templates_tutorial\toy1\source\app.d(19):
cannot pass argument `&addMyInts` 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(13):
`app.foo.doSomething(int function(int, int) doer)` declared here
int doSomething(int function(int, int) doer)
^
```
