@trusting generic functions

[Era Scarecrow via Digitalmars-d-learn]

On Saturday, 28 May 2016 at 12:25:14 UTC, Lodovico Giaretta wrote:
> The problem is that T is a type, and I should check for safety 
> of every method of T that I'm using in my function. This does 
> not scale well, and if I change the body of the function to use 
> a new method, I may forget to add it to the isSafe checks.

  I think i see what's going on then. Had to re-read it a few 
times. So ignore my previous reply.



  Easiest solution is to mark the entire struct as @safe or 
@trusted. Problem goes away (as long as you don't forcibly change 
it)

  Second is to force the check on the function before the call.

   static assert(isSafe!T.dosomething);
   pt.dosomething();

  Third... You could put in @safe code and have it complain? 
(might not work)

  @safe {
    pt.dosomething(); //if not @safe/@trusted it will refuse to 
compile
  }

  Fourth, you could create a helper function/template that cycles 
through a struct of your choice and tells you if any of it's 
methods fail to be safe. This will require a little more work, 
but it could be used as a full insurance and only requires a 
single template call on your function to ensure the safety.

  I can try and make this fourth one, but this isn't something 
I've done often.