封装 shared::mutex

由于未lock情况下调用unlock会导致异常,修改下
class MyClass : public shared_mutex
{
public:
bool islock;
void lock() {
shared_mutex::lock();
islock = true;

};void unlock() {     if (islock)    {        islock = false;         shared_mutex::unlock();    }};MyClass () { islock = false; };~MyClass() {};

private:

};