c++ - Calling of delete after construction throwing an exception -

i'm reading effective c++ 3rd edition, item52 "write placement delete if write placement new".

i want how make operator delete automatically called after construction throwing exception.

#include <iostream> using namespace std;  class {     int i; public:     static void* operator new(std::size_t size) throw(std::bad_alloc) {         return malloc(size);     }     static void operator delete(void* p) throw() {         cout << "delete" << endl;         free(p);     }     a() {         throw exception();     } };  int main() {     a* = new a; } 

the above codes output:

terminate called after throwing instance of 'std::exception'   what():  std::exception [1]    28476 abort      ./test_clion 

reference: operator delete, operator delete[]

i should write new in try {}. know little exceptions now.

#include <iostream> using namespace std;  class {     int i; public:     static void* operator new(std::size_t size) throw(std::bad_alloc) {         return malloc(size);     }     static void operator delete(void* p) throw() {         cout << "delete" << endl;         free(p);     }     a() {         throw exception();     } };  int main() {     try {         a* = new a;     } catch (const exception&) {      } } 

and output:

delete