Thread wrapper with custom destruct function - c++

Question

Let me start with a short example
class A
{
public:
A() :
thread_([this] {
std::unique_lock<std::mutex> lk(mtx_);
cv_.wait(lk, [this] { return quit_; });
})
{
throw std::exception();
}
~A()
{
quit_ = true;
cv_.notify_one();
thread_.join();
}
private:
bool quit_ = false;
std::mutex mtx_;
std::condition_variable cv_;
std::thread thread_;
};
int main()
{
try { A a; }
catch (...) {}
// Does not reach this point
}
Because an exception is thrown in the constructor, the members are being destructed in reverse order.
the thread_ member is still joinable so terminate is being called.
It is pretty straightforward to write a thread wrapper class with a customizable destructor.
For example, something like that:
class ThreadWrapper
{
public:
ThreadWrapper(std::function<void(std::thread & t)> onDestruct, std::thread&& thread) :
onDestruct_(onDestruct),
thread_(std::move(thread))
{
}
~ThreadWrapper()
{
onDestruct_(thread_);
}
private:
std::function<void(std::thread & t)> onDestruct_;
std::thread thread_;
};
class B
{
public:
B() :
thread_(
[this](std::thread& t) {
quit_ = true;
cv_.notify_one();
t.join();
},
std::thread([this] {
std::unique_lock<std::mutex> lk(mtx_);
cv_.wait(lk, [this] { return quit_; });
}))
{
throw std::exception();
}
private:
bool quit_ = false;
std::mutex mtx_;
std::condition_variable cv_;
ThreadWrapper thread_;
};
However, I was surprised not to find something like that in the boost library.
The closest thing I found is the scoped_thread which lets you pass a specific action as a template parameter.
Am I missing something?