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