Required constness of opEquals (and opCmp) ?

[Era Scarecrow]

On Wednesday, 2 January 2013 at 09:07:31 UTC, monarch_dodra wrote:
> My opinion is that supporting non-const opEquals makes no real 
> sense, and adds a lot of useless complexity (and inconsistency) 
> to the code. At best, it means silently accepting erroneous 
> code... Until it explodes in someone else's face...

  If the code doesn't change anything, it should be const.

  I know in a sorting algorithmn I am testing with I created a 
struct that held three numbers. The comparing number, and 
ordering number (to check against stable sorting) and a counter 
for how many times that number was compared against. So there 
could be uses for non-const versions, but those shouldn't affect 
the rest of the library for a few use cases.