text: #ifndef __GAYLE_CH01_EX11_HPP__
  #define __GAYLE_CH01_EX11_HPP__
  
  #include <string>
  
  /*! @brief Implement an algorithm to determine if a string
   *  has all unique characters. What if you can not use
   *  additional data structures */
  bool AllUnique(std::string const &rhs);
  
  #endif