On Friday, 25 July 2014 at 08:02:18 UTC, Jacob Carlborg wrote:
1. If neither opCmp or opEquals are defined, the compiler will
automatically generate these and will be used for comparison
and equivalent
2. If opEquals is defined, lhs == rhs will be lowered to
lhs.opEquals(rhs)
3. If opCmp is defined but no opEquals, lhs == rhs will be
lowered to lhs.opCmp(rhs) == 0
4. If opCmp and opEquals is defined, lhs == rhs will be lowered
to lhs.opEquals(rhs)
The compiler _never_ defines opCmp for you. You have to do that
yourself. So, what you're suggesting would force people to define
opEquals just because they defined opCmp unless they wanted to
take a performance hit. And once you define opEquals, you have to
define toHash. So, what you're suggesting would force a lot more
code to define toHash, which will likely cause far more bugs than
simply requiring that the programmer define opEquals if that's
required in order to make it consistent with opEquals.
- Jonathan M Davis
