std::random_shuffle / std::shuffle swap element with itself (move element to itself).

main.cpp

#include <algorithm>
#include <cassert>
#include <vector>
#include <random>

using namespace std;

struct Foo {
 public:
  Foo() {}

  Foo &operator=(Foo &&other) {
    assert(&other != this);
    return *this;
  };

  Foo(Foo &&other) {
    assert(&other != this);
  }
};

int main() {
  vector<Foo> vec(1337);

  random_shuffle(vec.begin(), vec.end());
  
  //mt19937 g;
  //shuffle(vec.begin(), vec.end(), g);
  
  return 0;
}

Use http://webcompiler.cloudapp.net/ to run.

Related libstdc++ bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59603

libc++ seems to protect against it, in at least two of three cases: https://github.com/llvm-mirror/libcxx/blob/master/include/algorithm#L3079