Re: Required Reading: "How Non-Member Functions Improve Encapsulation"

[Steven Schveighoffer via Digitalmars-d]

On 10/25/17 6:19 PM, Walter Bright wrote:
for core D devs.
"How Non-Member Functions Improve Encapsulation" by Scott Meyers

http://www.drdobbs.com/cpp/how-non-member-functions-improve-encapsu/184401197 


Note that I'm as guilty as anyone for not understanding or following 
these guidelines. I expect we can do much better.

I'm pretty sure I read that before.

However, D's lookup rules fail miserably when it comes to templates:

mod1.d:

auto callFoo(T)(T t)
{
  return t.foo;
}

mod2.d:

struct S
{
   int x;
}

int foo(S s) { return s.x * 5; }

void main()
{
   auto s = S(1);
   assert(s.foo == 5);
   assert(s.callFoo == 5); // can't compile
}

Would be nice to have a way around this. Not sure what it would look like.

Also in D, it's harder to make this help for encapsulation since the 
non-member functions would have to be in another module.

-Steve