nothrow function callbacks in extern(C) code - solution

[anonymous via Digitalmars-d]

On Thursday, 19 June 2014 at 22:22:33 UTC, w0rp wrote:

> I haven't yet figured out a good way to make opApply 
> implementations get all of the nice qualifiers without writing 
> a bunch of overloads.

I don't know how practical this is, but since attributes are
inferred for templated methods ...

struct S
{
      int opApply(Dg : int delegate(ref int))(Dg dg)
      {
          int e;
          return dg(e);
      }
}
void f1() pure nothrow @nogc @safe
{
      S s;
      foreach(int x; s) {}
}
void f2()
{
      S s;
      import std.stdio;
      foreach(int x; s) writeln(x);
}
void main()
{
      f1();
      f2();
}