What is the difference between type traits and type classes?

What is the difference between type traits and type classes?

Type traits are a C++ feature that allows you to query or modify types at compile time, while type classes are a Haskell feature that enable polymorphism by defining a set of functions that can operate on different types.

Can you give me an example of type traits in C++?

Sure! In C++, you can use std::is_integral to check if a type is an integral type. For example:

#include <type_traits>

if (std::is_integral<int>::value) {
    // This will be true
}

And how about an example of type classes in Haskell?

In Haskell, you might define a type class like this:

typeclass Show a where
    show :: a -> String

Then, you can create instances of this type class for different types, allowing them to be converted to a string.

Are there any performance implications when using these features?

Yes, type traits can lead to more optimized code at compile time, while type classes may introduce some runtime overhead due to dynamic dispatch, depending on how they are implemented.