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  1. #include <iostream>
  2. using namespace std;
  3.  
  4. constexpr unsigned long djb2_hash_impl( const char* text, unsigned long prev_hash )
  5. {
  6.     return text[0] == '\0' ? prev_hash : djb2_hash_impl( &text[1], prev_hash * 33 ^ static_cast<unsigned long>(text[0]) );
  7. }
  8.  
  9. constexpr unsigned long djb2_hash( const char* text )
  10. {
  11.     return djb2_hash_impl( text, 5381 );
  12. }
  13.  
  14. enum EXAMPLE
  15. {
  16. 	VAL = djb2_hash( "Hello World" )
  17. };
  18.  
  19. int main() {
  20.     auto hello_hash = djb2_hash( "Hello World" );
  21.  
  22.     switch( hello_hash )
  23.     {
  24.         case djb2_hash( "Hello World" ):
  25.             cout << "Hash matched with value " << hello_hash << endl;
  26.             break;
  27.         default:
  28.             cout << "Hash did not match" << endl;
  29.     }
  30.  
  31.     cout << "And the enum has value of " << VAL << endl;
  32.     return 0;
  33. }
Success #stdin #stdout 0s 3344KB
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stdin
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Standard input is empty
stdout
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Hash matched with value 903737989
And the enum has value of 903737989
https://ideone.com/uHpEvY
language:
C++14 (gcc 8.3)
created:
9 years ago
visibility:
public

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