Re: Can I pass a function by parameter?

[AsmMan via Digitalmars-d]

On Sunday, 7 September 2014 at 21:23:26 UTC, Jakob Ovrum wrote:
On Sunday, 7 September 2014 at 21:02:16 UTC, John Colvin wrote:
bool g(int n) { ... }
f(arr, &g);

This will fail if `&g` is a function pointer, such as when `g` 
is declared at module-level scope. In that case, it has to be 
explicitly converted to a delegate:

---
import std.functional : toDelegate;

int f(in int[] arr, bool delegate(int) func);
bool g(int n) { ... }
f(arr, toDelegate(&g));
---

Alternatively, make `f` receive a function pointer instead of a 
delegate:

---
int f(in int[] arr, bool function(int) func);
bool g(int n) { ... }
f(arr, &g);
---

Thank you too. Btw, why the & operator in this syntax? I used to 
think ref keyword sort of C's T** and & operator is neeeded.. or 
is it because f can be a function called without pass any 
parameter?