Create shared_lock or unique_lock based on a condition

Question

I need to create unique_lock or shared lock based on a parameter in my function. I couldn't define properly in the scope of function. So I need to do something like this.

function (bool check) {
 lock;
 if (check) {
  lock = std::unique_lock<std::shared_mutex>(mutex);
 } else {
  lock = std::shared_lock<std::shared_mutex>(mutex);
 }
 lock.lock();
 doTask....

Answer 1

Like this?

void function (bool check) {
  std::unique_lock<std::shared_mutex> u(mutex, std::defer_lock);
  std::shared_lock<std::shared_mutex> s(mutex, std::defer_lock);
  if (check) {
    u.lock();
  } else {
    s.lock();
  }
  doTask....