Infix operators as first-class functions

[Dretch]

Infix operators can't be used like normal functions. Instead of:

std::sort::merge_sort(<=, some_strs)

one must write:

std::sort::merge_sort({|a, b| a <= b}, some_strs)

It would be nice to not have to write the lamda.

[brson]

This doesn't directly address your issue but most types have standard comparison functions defined, like uint::le. There's an additional problem with them though, that they are usually defined with by-value parameters, but generic functions expect by-ref parameters. We could also define something like core::univ that defines all the universal operators over generic types, like eq, ne, lt, gt, le, ge.

[catamorphism]

I agree with @Dretch that this is a nice idea (I used it all the time in Haskell), but in general, we're trying to remove features from the language rather than add them. If you are passionate about it, though, please open a new bug and follow the RFC process: https://github.com/mozilla/rust/wiki/Note-RFC-process

Closing this for now.