language: C++11 (gcc-4.7.2)
date: 561 days 10 hours ago
link:
visibility: private 
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#include <cstdlib>
#include <utility>
#include <memory>
#include <iostream>
 
template< typename Ret, typename Last >
Ret random_picker_impl( size_t i, Last&& last )
{
   return std::forward<Last>(last);
}
 
template< typename Ret, typename First, typename Second, typename ... Rest >
Ret random_picker_impl( size_t i, First&& first, Second&& second, Rest&&... rest )
{
   if( i == 0 )
   {
      return std::forward<First>(first);
   }
   else
   {
      return random_picker_impl<Ret>( i-1, std::forward<Second>(second), std::forward<Rest>(rest)... );
   }
}
 
template< typename First, typename ... Rest >
First random_picker( First&& first, Rest&&... rest )
{
   size_t index = (sizeof...(rest) + 1) * (std::rand() / double(RAND_MAX));
   return random_picker_impl<First>( index, std::forward<First>(first), std::forward<Rest>(rest)... );
}
 
int main()
{
   for( int i=0; i<20; ++i )
   {
      std::unique_ptr<int> a(new int(1));
      std::unique_ptr<int> b(new int(1));
      std::unique_ptr<int> c(new int(1));
      auto i = random_picker( a, b, c );
      std::cout << "chose: " << *i.get() << '\n';
   }
}
/usr/lib/gcc/i686-pc-linux-gnu/4.5.1/../../../../include/c++/4.5.1/bits/unique_ptr.h: In function 'int main()':
/usr/lib/gcc/i686-pc-linux-gnu/4.5.1/../../../../include/c++/4.5.1/bits/unique_ptr.h:207:7: error: deleted function 'std::unique_ptr<_Tp, _Tp_Deleter>::unique_ptr(const std::unique_ptr<_Tp, _Tp_Deleter>&) [with _Tp = int, _Tp_Deleter = std::default_delete<int>, std::unique_ptr<_Tp, _Tp_Deleter> = std::unique_ptr<int>]'
prog.cpp:39:39: error: used here