C++11: User-defined Literals

A User-defined literal is a constant that has a suffix that a class can define an operator for to handle. Here is an example:

#include &ltcmath&gt
#include &ltiostream&gt
int operator ""_z(unsigned long long i) { return (int)std::pow(2, i); }
int main()
{
  std::cout << 5_z << std::endl;
  return 0;
}
// Output: 32

Reference: https://isocpp.org/wiki/faq/cpp11-language#udls