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Comment by runT1ME | Hacker News Reader

>Haskell introduced typeclasses. Go and Rust popularize them (as interfaces and traits, respectively, the latter also influenced by C++ STL's concepts).

This is a really ironic thing to say considering Go doesn't have generics, rust doesn't have higher kinds, they don't support any sort of implicit (or global) way of using them as constraints.... are you sure you know what type classes are?

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This may be true about Go, but Rust's traits were very similar to Haskell type classes and now are equivalent in power to Haskell's type classes with several extensions turned on (even though they lack HKTs).

As a side note although clunky HKTs are encodable in Rust and I plan on implementing them natively once we have landed a stable version of 1.0.

How do you enforce them as constraints on a method?

    pub trait SomeTrait { ... }

    pub fn some_function<T: SomeTrait>(arg: T) { ... }

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