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  1. #include <iostream>
  2. #include <string>
  3. #include <stdint.h>
  4.  
  5. /////////////////////////
  6. // strings as case labels
  7. //////////////////////////
  8.  
  9. constexpr uint32_t djb2Hash(const char* str, int index = 0)
  10. {
  11.     return !str[index]
  12.         ? 0x1505
  13.         : (djb2Hash(str, index + 1) * 0x21) ^ str[index];
  14. }
  15.  
  16. // Create a literal type for short-hand case strings
  17. constexpr unsigned int operator"" _C(
  18.     const char str[], size_t size)
  19. {
  20.     return djb2Hash(str);
  21. }
  22.  
  23. void Bloblawblah(const std::string& cond)
  24. {
  25.     switch(djb2Hash(cond.c_str()))
  26.     {
  27.     case "Hello"_C: std::cout << "Goodbye"; break;
  28.     case "World"_C: std::cout << "Planet"; break;
  29.     default: std::cout << "BOGUS!";
  30.     }
  31.     std::cout << std::endl;
  32. }
  33.  
  34. int main()
  35. {
  36.     Bloblawblah("Hello");
  37.     Bloblawblah("World");
  38.     Bloblawblah("Error");
  39. }
  40.  
  41.  
Success #stdin #stdout 0s 2984KB
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stdin
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Standard input is empty
stdout
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Goodbye
Planet
BOGUS!
https://ideone.com/q8NSEn
Strings in case labels (LinkedIn)
language:
C++14 (gcc 8.3)
created:
12 years ago
visibility:
public

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