Boost C++ Libraries: Ticket #610: object destructor called four times when using thread

zigmar — Thu, 27 Apr 2006 15:04:51 GMT

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You pass the test object (a) by value, so the behaviour is
probably correct. When you see, is the destruction of
temporary objects. You will able to see their construction
if you add custom copy constuctor to test class. Now, you
print the message only when original object is created, but
not when it copy-constructed. Try this:
class test {
public:
  test() {
    cout << "constructor" << endl;
  };
  test(const test&) {
    cout << "copy constructor" << endl;
  };
  ~test() {
    cout << "destructor" << endl;
  };
};

status changed

Roland Schwarz — Sun, 01 Oct 2006 13:57:47 GMT

status assigned → closed

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This is a consequence of your code tracing only default
constructor calls, and all destructor calls.
If you override the default compiler generated copy
constructor like:
test(const test& t) {
  *this = t;
  cout << "copyconstructor" << endl;
}
you will see that each constructor call indeed is matched by
a destructor call. (with exception of course that you code
never destroys a, which leaves a leak)