Zufallszahlen in C++ 

    std::random_device r;
    // std::default_random_engine e1(r()); // hat nur sehr kurze Periode, hier schlecht
    std::mt19937 e1(r()); // besser, größere Periode
    std::uniform_int_distribution<int> uniform_dist100(2, 99);
#define _GLIBCXX_USE_RANDOM_TR1
#include <iostream>
#include <ostream>
#include <random>
int main()
{ ::std::default_random_engine default_engine;
  ::std::uniform_int_distribution< int >dice_distribution{ 1, 6 };
  auto const dice =[ & ]()-> int{ return dice_distribution( default_engine ); };
  for( int i = 6; i--; )::std::cout << dice() << '\n'; }
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#define _GLIBCXX_USE_RANDOM_TR1
#include <iostream>
#include <ostream>
#include <random>
#include <ctime>
int main()
{ ::std::uniform_int_distribution< int >dice_distribution{ 1, 6 };
  ::std::default_random_engine default_engine( ::std::time( 0 ));
  auto const dice =[ & ]()-> int{ return dice_distribution( default_engine ); };
  for( int i = 6; i--; )::std::cout << dice() << '\n'; }
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#define _GLIBCXX_USE_RANDOM_TR1
#include <random>
#include <algorithm>
#include <iterator>
#include <iostream>
#include <ctime>
int main()
{ ::std::string str{ "abcdefghijklmnopqrstuvwxyz" };
  ::std::default_random_engine default_engine( ::std::time( 0 ));
  ::std::shuffle( begin( str ), end( str ), default_engine );
  ::std::cout << str << "\n"; }
lfpwatxbsydqigmknrvjouhezc
#include <iostream>
#include <ostream>
#include <random>
int main()
{ ::std::cout << ::std::random_device{}.entropy() << "\n"; }
0

Notizen

#define _GLIBCXX_USE_RANDOM_TR1
#include <random>
#include <chrono>
::std::mt19937_64  engine
( static_cast<unsigned>(std::chrono::system_clock::now().time_since_epoch().count()) *
  static_cast<unsigned>(std::chrono::system_clock::now().time_since_epoch().count()));
::std::uniform_real_distribution< double >distribution( 0.0, 1.0 );
distribution( engine ); distribution( engine ); distribution( engine );
x = distribution( engine )
|GCC 4.6+ and Clang 3.2+ provide intrinsic functions for
|RdRand when -mrdrnd is specified in the flags,[20] also
|setting __RDRND__ to allow conditional compilation.
en.wikipedia.org/wiki/RdRand