The function std::shuffle has been introduced in C++11:
template< class RandomIt, class URNG >
void shuffle( RandomIt first, RandomIt last, URNG&& g );
and it has the same signature as one of the overloads of std::random_shuffle which was also introduced in C++11:
template< class RandomIt, class RandomFunc >
void random_shuffle( RandomIt first, RandomIt last, RandomFunc&& r );
The difference is in the third parameter where:
URNG must meet the requirements of UniformRandomNumberGenerator
Is this all? Is the difference just that shuffle performs an extra compile time check? Is the behavior otherwise the same?
If you read the documentation at cppreference.com closely, you will find that the RandomFunc passed to random_shuffle has a different interface. It is invoked as r(n). This existed before C++11.
std::shuffle uses a standardized way of getting random numbers and invokes g(). This standardized random number generators where introduced with C++11 together with std::shuffle.
std::random_shuffle uses std::rand() function to randomize the items, while the std::shuffle uses urng which is a better random generator, though with the particular overload of std::random_shuffle, you can get the same behavior (as with the std::shuffle) but that requires you to do some work to pass the third argument.
Watch this talk by Stephan T. Lavavej, in which he explains why std::rand is a bad function and what C++ programmers should use instead:
The gist is, std::shuffle is an improvement over std::random_shuffle, and C++ programmers should prefer using the former.
来源：https://stackoverflow.com/questions/19219726/what-is-the-difference-between-shuffle-and-random-shuffle-c