#include <mutex>
#include <iostream>
using namespace std;
 
struct LoudMutex : std::mutex {
	using std::mutex::mutex;
	void lock() { cout << "Locking!" << endl; this->mutex::lock(); }
 
	bool try_lock() { cout << "Trying to lock: " << endl;
					  bool success = this->mutex::try_lock();
					  cout << success << endl;
					  return success; }
 
	void unlock() { cout << "Unlocking!" << endl; this->mutex::unlock(); }
};
 
int main() {
	LoudMutex m;
 
	{
		cout << endl << "Case 1" << endl;
		std::unique_lock<LoudMutex> l(m);
		cout << "Hello!" << endl;
	}
 
	{
		cout << endl << "Case 2" << endl;
		auto l = std::unique_lock<LoudMutex>(m);
		cout << "Hello!" << endl;
	}
 
	{
		cout << endl << "Case 3" << endl;
		// OOPS! this declares a function `l`, but doesn't invoke any methods!
		auto l(std::unique_lock<LoudMutex>(m));
		cout << "Hello!" << endl;
	}
 
	return 0;
}

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