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Comment by andrepd | Hacker News Reader

This in cpp:

    template<class T> 
    constexpr const T& max(const T& a, const T& b) {
        return a>b ? a : b;
    }

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Edit: apologies, I'm blind; never mind. I thought I double-checked but the use of > instead of < tripped me up.

Stepanov disagrees. You should return the second parameter if a, b are equivalent (and you should use < anyway):

  template<typename T>
  inline constexpr const T& max(const T& a, const T& b) {
     return (b < a ? a : b);
  }

What’s the reasoning behind this?

I think to be comparable in c++ types are required to implement < operator and the same is exclusively used by the stdlib.

If you sort2(a, b), it would be nice if min(a, b) == a && max(a, b) == b.

The C version works with distinct types for a and b. Does this?

That's not a feature, it's more bug prone.

This one works too, if they are implicitly convertible (e.g. max(1, 2.0))

No it won't. You'll get a compile time error, as T could either deduce to int or double. Unless you explicitly specify it as max<int>(1, 2.0) or max<double>(1, 2.0).

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