Re: Operator overloading or alternatives to expression templates

[Andrei Alexandrescu via Digitalmars-d]

On 09/13/2015 03:06 PM, Martin Nowak wrote:
On 09/13/2015 07:16 PM, Daniel N wrote:

Could you try this?

int opCmp(Foo rhs)
{
   return (id > rhs.id) - (id < rhs.id);
}

That's not the point, opCmp requires twice as many comparisons as needed
for <. If they are more expansive, e.g. string comparison, your trick
won't work.

Well for string comparisons, the added cost (if not optimized away) is 
constant. Overall it seems to me that D is to be appreciated for 
requiring only one operator for all ordering comparisons (it causes a 
lot of noise in C++). Reducing comparisons is the job of the optimizer. 
Expression templates are a possible loss, but of a questionable trick. 
-- Andrei