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Special operator for one type? Please no.

Well, this is C++, so the spaceship operator can be overloaded for all sorts of clever purposes.

For example, when comparing strings, you could use it to coerce the arguments into spaceship objects, then run a little Space War simulation to lighten the user's day. Just another day of C++ operator overloading.

No, it could be used for any type. It would be equivalent to (a<b)&&(a==b)&&(a>b), but would be most useful for floating point, where this operator would evaluate to false if a or b is NaN.

Nope, this operator will always evaluate to false. Show me any pair of numbers, which is not NaN, which will be at the same time, equal, smaller, and greater. Of course I can imagine such a set, and operations... (I have a little bit of a mathematical background) but for programming it will be quite useless.

Why not `is_nan()` insted?

No, the operator is like the same operator in Ruby. You define an operator<=> for one or two types and then whenever you use one of the normal comparison operators in code (say a < b), the compiler replaces it with a<=>b < 0.

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