...S {
  float a, b;

  alias opBin = float delegate();
  opBin[string] ops;
}

void main() {
    S s...

...the delegate? What exactly do you want to do?  Set after constructor or assign delegate...

...error

  Fix 2525: make forAllInterfaces take a delegate

  issue 2525: add unit tests

  issue 2525...

...scope int delegate(string)       callback)
    { return callback(""); }
}
struct S2
{
    int opApply     (scope int delegate(string...

...a `@called` attribute that indicates the function delegate may be called inside the function, meaning...

...we can write:

```d
void callInSequence(void delegate() attrib @safe dgs[])
{
    foreach(dg; dgs)
        dg...

...types that include delegate or function pointer types somewhere: Slices of delegate or function pointer...

...when the delegate takes parameters, say `int`:
```D
/*A*/ void process(void delegate(int) callback...

Code:

````
void process()(void delegate() cb) { cb(); }

void gcFunc() {
	int[] a;
	process({ a = new int...

Consider:

 void delegate() dg;

 // no error
 void process(void delegate() userData) @nogc { dg = userData; }

 // Error...