utx::real_number is a concept of utxcpp that requires the types must satisfy integral or floating point requirements.
It means real number in math.
c++ example
#include <utxcpp/core.hpp> template <utx::real_number type_xta> class my_data { }; int main() { my_data<utx::i32> d1; // OK //my_data<utx::ix32> d2; // ERROR: utx::ix32 is class type of utx::i32 static_assert(utx::real_number<utx::i32>); static_assert(! utx::real_number<utx::ix32>); utx::real_number auto a = 345; // a is int utx::real_number auto b = 3.45; // b is double }