[llvm] [CommandLine] Make options of copyable class types get reset to their provided initial values (PR #173026)

[Nikita Popov via llvm-commits]

nikic wrote:

Thanks for the update!

I have a similar question for compare() and non-comparable types. Having a compare() method that sometimes is hardcoded to return false seems like a footgun. Where do these non-comparable types show up? Would it be viable to guard the entire method by enable_if so that using compare() with a non-comparable type is a compile error instead of silent misbehavior?

https://github.com/llvm/llvm-project/pull/173026