Modern C++ Programming Cookbook

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Composition is usually represented by a dot (.) or asterisk (*), such as f . g or f * g. We can actually do something similar in C++ by overloading operator* (it would make little sense to try to overload operator dot). Similar to the compose() function, operator* should work with any number of arguments; therefore, we will have two overloads, just like in the case of compose():

• The first overload takes two arguments and calls compose() to return a new function.
• The second overload is a variadic template function that again calls operator* by expanding the parameter pack:

    template <typename F, typename G>     auto operator*(F&& f, G&& g)     {       return compose(std::forward<F>(f), std::forward<G>(g));     }  template <typename F, ...