example/enum.cpp

   1 // (C) Copyright Vesa Karvonen 2004.
   2 //
   3 // Distributed under the Boost Software License, Version 1.0.
   4 // (See accompanying file LICENSE.)
   5
   6 # include <iostream>
   7 # include "enum.hpp"
   8
   9 // ### Usage
  10 //
  11 // To demonstrate the use of the `ENUM'-macro, we'll write a simple
  12 // `ENUM'-specification:
  13 //
  14 //<
  15 ENUM(naked_gun,
  16      (from_the_files_of_police_squad, 1)
  17      (the_smell_of_fear)
  18      (the_final_insult, 33))
  19 //>
  20 // Then we'll use the generated conversion functions and output the
  21 // strings returned by the `to_string'-function:
  22 //<
  23 int main(void) {
  24   std::cout
  25     << to_string(to_naked_gun("from_the_files_of_police_squad"))
  26     << '\n'
  27     << to_string(to_naked_gun("the_smell_of_fear"))
  28     << '\n'
  29     << to_string(to_naked_gun("the_final_insult"))
  30     << '\n';
  31
  32   return 0;
  33 }
  34 //>
  35 //
  36 // \begin{exercise}
  37 // The conversion from the value of an enumerator to a string can be
  38 // done in constant time easily when the values of the enumerators
  39 // are known to be consecutive. This is known to be the case when
  40 // all but the first enumerator use the default value. Implement the
  41 // constant time conversion as an optimization.
  42 // \end{exercise}
  43 //
  44 // \begin{exercise}
  45 // Extend the `ENUM'-macro to optionally generate a standard stream
  46 // inserter and a stream extractor for the defined enumerated type.
  47 // \end{exercise}
  48 //
  49 // \begin{exercise}
  50 // Extend the `ENUM'-macro to optionally generate constructors for
  51 // the enumerated type. The constructors should check that that the
  52 // specified integral value or string identifier is one of the
  53 // enumerators and throw an exception if that is not the case.
  54 // \end{exercise}