C++ operator () overloading

Question

Could anybody explain what this code does?

struct EnumClass
    {
        template <typename T>
        std::size_t operator()(T t) const
        {
            return static_cast<std::size_t>(t);
        }
    };

Does this answer your question? [What are C++ functors and their uses?](https://stackoverflow.com/questions/356950/what-are-c-functors-and-their-uses) — rezaebrh, Jan 06 '20 at 13:03

DevSolar · Accepted Answer · 2020-01-06T08:44:52.413

6

It defines the operator () for any object of type EnumClass, taking one argument of any type. The operator evaluates to that argument, cast to type size_t.

EnumClass e;
e(1); // evaluates to (size_t)1

This is borderline nonsense, of course. (It might make sense in some other context, but stand-alone and as-is, it doesn't -- you don't need an EnumClass object to cast something to size_t.)

edited Jan 06 '20 at 08:44

answered Jan 06 '20 at 08:32

DevSolar

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C++ operator () overloading

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