| 1 | #ifndef BOOST_MOVE_TEST_RANDOM_SHUFFLE_HPP |
|---|---|
| 2 | #define BOOST_MOVE_TEST_RANDOM_SHUFFLE_HPP |
| 3 | |
| 4 | |
| 5 | #include <boost/move/adl_move_swap.hpp> |
| 6 | #include <boost/move/detail/iterator_traits.hpp> |
| 7 | #include <stdlib.h> |
| 8 | |
| 9 | inline unsigned long long rand_15_bit() |
| 10 | { |
| 11 | //Many rand implementation only use 15 bits |
| 12 | //so make sure we have only 15 bits |
| 13 | return (unsigned long long)((std::rand()) & 0x7fff); |
| 14 | } |
| 15 | |
| 16 | inline unsigned long long ullrand() |
| 17 | { |
| 18 | return (rand_15_bit() << 54u) ^ (rand_15_bit() << 39u) |
| 19 | ^ (rand_15_bit() << 26u) ^ (rand_15_bit() << 13u) |
| 20 | ^ rand_15_bit(); |
| 21 | } |
| 22 | |
| 23 | template< class RandomIt > |
| 24 | void random_shuffle( RandomIt first, RandomIt last ) |
| 25 | { |
| 26 | std::size_t n = std::size_t (last - first); |
| 27 | for (std::size_t i = n-1; i > 0; --i) { |
| 28 | std::size_t j = static_cast<std::size_t >(ullrand() % (unsigned long long)(i+1)); |
| 29 | if(j != i) { |
| 30 | boost::adl_move_swap(first[i], first[j]); |
| 31 | } |
| 32 | } |
| 33 | } |
| 34 | |
| 35 | |
| 36 | #endif// BOOST_MOVE_TEST_RANDOM_SHUFFLE_HPP |
| 37 |