[msbarnett]

> Only if you do it that way. Make it MatchForParticularPurpose(v1, v2) instead, and voila no leak.

Making the name more opaque won't save you at all. You're making what should be a local detail -- how your type implements equality -- into something that only works when it is global knowledge.

Consequently, your type is brittle and incomposable with types that aren't infected with this knowledge:

    [instance11, instance2, instance3].sort

won't do anything sensible until we infect either the Array type or the call site with non-local knowledge about your type.

Every type you build in this manner will find knowledge about itself diffusing throughout your application, like children peeing in a pool. Composition will be limited, inflexible, and require manual insertion of type-specific knowledge, because you have failed to encapsulate knowledge about equality.

Everything needs to know about everything else, and in the end you've built a tightly coupled ball of mud.