Ray Ray - 1 year ago 168
C++ Question

Compilation error : 'this' cannot be implicitly captured in this context

I am trying to add a condition_variable to handle threads, but get a compilation error at this line:

this->cv.wait(lk, []{return this->ready;});


Looks like the for the variable this->ready, the 'this' is not in the right scope.

In Java this can be handled with TestThread.this, is there anything in C++ doing the same?

void TestThread::Thread_Activity()
{
std::cout << "Thread started \n";
// Wait until ThreadA() sends data
{
std::unique_lock<std::mutex> lk(m);
this->cv.wait(lk, []{return ready;});
}

std::cout << "Thread is processing data\n";
data += " after processing";
// Send data back to ThreadA through the condition variable
{
// std::lock_guard<std::mutex> lk(m);
processed = true;
// std::cout << "Thread B signals data processing completed\n";
}

}

Answer Source

You need to capture the this pointer:

this->cv.wait(lk, [this]{return ready;});
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