c++ - Why does double free or corruption error not happen at run time for boost ptr_container? -

i testing out boost ptr_containers , wrote small program below:

class test {     public:         ~test() {             cout << "test destructor called" << endl;          } };  int main(int argc, char** argv) {      boost::ptr_map<int, test> testcontainer;     boost::ptr_vector<test> testvector;     (int i=0; i<2; ++i) {         test* ptr = new test();         testcontainer.insert(i, ptr);         testvector.push_back(ptr);     }  } 

once execute program, "test destructor called" printed 4 time , program completes successfully. expecting printing happen 2 times , "doube free..." error message thrown. why not happen in above case, happens raw pointer (test*)?

ptr_map , ptr_vector own elements.

the program incorrect. inserting same elements in 2 containers @ once leads double deletion.

the behaviour of delete on already-deleted pointer undefined. can happen. see undefined behaviour

use tool valgrind catch this.

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in case did want know, easiest way fix sample using non-owning pointers 1 of containers. sure manage relative lifetimes of elements:

#include <boost/ptr_container/ptr_vector.hpp> #include <iostream> #include <map>  class test {     public:         ~test() {             std::cout << "test destructor called" << std::endl;          } };  int main() {      boost::ptr_vector<test> testvector;     {         std::map<int, test*> testcontainer;          (int i=0; i<2; ++i) {             test* ptr = new test();             testcontainer.emplace(i, ptr);             testvector.push_back(ptr);         }     }  }