A predicate for stl algorithm should always be stateless
void test_remove_if_bug()
{
list<int> coll = {
1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
cout<<"coll: ";
std::copy(coll.begin(), coll.end(), ostream_iterator<int>(cout, " "));
cout<<endl;
// remove third element
list<int>::iterator pos;
int n = 3;
int cur = 0;
//ok
// pos = remove_if(coll.begin(), coll.end(), // range
// [&](const auto &e) {
// return ++cur == n;
// }); // remove criterion
//bug
pos = remove_if(coll.begin(), coll.end(), // range
[=](const auto &e) mutable {
return ++cur == n;
}); // remove criterion
coll.erase(pos, coll.end());
cout<<"3rd removed: ";
std::copy(coll.begin(), coll.end(), ostream_iterator<int>(cout, " "));
cout<<endl;
}