Hello,
Consider this example:
```d
module foo;
import std.stdio;
import std.algorithm;
import std.traits;
import std.range;
void print(R)(R r) {
static assert(isIterable!R);
r.each!writeln;
}
auto construct(R)(R r, ElementType!R delegate(ulong i) fn) {
static assert(isIterable!R && hasAssignableElements!R);
ulong i = 1;
r.each!((ref e) => e = fn(i));
return r;
}
unittest {
int[] i; i.length = 4;
i.construct((ulong i) {return cast(int)(i+i);}).print;
}
```
```shell
dmd -unittest -main foo.d
Error: template 'foo.construct' cannot deduce function from
argument types '!()(int[], int function(ulong i) pure nothrow
@nogc @safe)', candidates are: 'construct(R)(R r, ElementType!R
delegate(ulong i) fn)'
```
Where's **pure nothrow @nogc @safe** coming from?
Also, why is *(ulong i) {return cast(int)(i+i);}* passed as a
function?
The error message for passing a delegate is the same except with
*function* substituted for *delegate*.
