While testing mixed-lang-stack I realized that valgrind actually
complained about a double free in the test.
All done
==2503051==
==2503051== HEAP SUMMARY:
==2503051== in use at exit: 0 bytes in 0 blocks
==2503051== total heap usage: 26 allocs, 27 frees, 87,343 bytes allocated
==2503051==
==2503051== All heap blocks were freed -- no leaks are possible
==2503051==
==2503051== For lists of detected and suppressed errors, rerun with: -s
==2503051== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
Reason for this is that in mixed-lang-stack.cpp in mixed_func_1f an
object "derived_type obj" goes on the stack which is then passed-by-value
(so copied) to mixed_func_1g. The default copy-ctor will be called but,
since derived_type contains a heap allocated string and the copy
constructor is not implemented it will only be able to shallow copy the
object. Right after each of the functions the object gets freed - on the
other hand the d'tor of derived_type actually is implemented and calls
free on the heap allocated string which leads to a double free. Instead
of obeying the rule of 3/5 I just got rid of all that since it does not
serve the test. The string is now just a const char* = ".." object
member.
