3 ms·

You still have to 'free' in destructors in C++. Destructors don't free your memory for your custom types for you.

• vinkelhake 13y ago
  The point is that the 'free' is now in one place and not in every place that uses the class.
• T-zex 13y ago
  You mean heap allocated types? Stack allocated will be deallocated implicitly.
• dllthomas 13y ago
  You need to free heap-allocated objects, but stack allocated objects are important and useful (particularly with RAII) and cleanly reversing such allocations eliminates a class of bugs.
  • jlarocco 13y ago
    Stack allocated objects are cleaned up automatically in C, too...
    • dllthomas 13y ago
      RAII. [1] Stack allocated objects have their memory freed in C. Other resources are not released. Consider the following C, with and without gcc extensions: #include <stdio.h> #include <stdlib.h> #include <malloc.h> #include <fcntl.h> #include <unistd.h> #ifndef GCC_EXTENSIONS #define GCC_EXTENSIONS 1 #endif int main() { { #if GCC_EXTENSIONS void close_fd(int *fdp) { if(*fdp >= 0) close(*fdp); } #else #define __attribute__(...) #endif int fd __attribute__((cleanup(close_fd))) = -1; fd = open("somefile", O_CREAT | O_WRONLY, 0644); system("ls /proc/self/fd"); } system("ls /proc/self/fd"); } with gcc extensions: 0 1 2 3 4 0 1 2 3 without gcc extensions: 0 1 2 3 4 0 1 2 3 4 [1] http://en.wikipedia.org/wiki/Resource_Acquisition_Is_Initialization http://en.wikipedia.org/wiki/Resource_Acquisition_Is_Initial...
  • mike-cardwell 13y ago
    And of course, you don't even need to explicitly free heap-allocated objects if you're using C++11 smart pointers like shared_ptr and unique_ptr.
    • dllthomas 13y ago
      ... mostly. Much like in a garbage collected language, you need to make sure you are no longer referencing things when you want resources to be freed, but it does make the worst case much harder to run into.