C++17 example of function type erasure with automated conversion to original types.

using Command = function<string(const vector<string>&)>;
Command command = BindCommand([](int a, int b) {
    return a + b;
});

// returns 12+7=19
command({ "12", "7" });

Use Clang 5.0+ or GCC 7.0+ in C++17 mode. Other compilers may fail.

• There is charconv_hack.h header which stubs std::from_chars function which is not available in libc++ yet. If you have <charconv> header, you can remove or disable charconv_hack.h