An object of type T stored in dynamic memory (heap) can be safely deleted through pointer of type void* only if T is a POD type.
POD types are:
where
Scalar types are:
Example 1: int is a POD type
Example 2: struct B is a POD type
Example 3: struct C is not a POD type
Memory leak is reported in debug output window when running Example 3:
This last example yields memory leak because delete applied to void* pointer freed memory allocated for C members but it did not call C destructor thus leaving memory pointed by p_ allocated.
POD types are:
- scalar types
- POD classes
- arrays of such types and
- cv-qualified versions of these types
where
Scalar types are:
- arithmetic(fundamental) types (like bool, char, int, float, double,...)
- enumeration types
- pointer types
- pointer to member types
- std::nullptr_t
- cv-qualified versions of these types
Example 1: int is a POD type
Example 2: struct B is a POD type
Example 3: struct C is not a POD type
Memory leak is reported in debug output window when running Example 3:
Detected memory leaks!
Dumping objects ->
{144} normal block at 0x00595580, 4 bytes long.
Data: < > 01 00 00 00
Object dump complete.
Dumping objects ->
{144} normal block at 0x00595580, 4 bytes long.
Data: < > 01 00 00 00
Object dump complete.
This last example yields memory leak because delete applied to void* pointer freed memory allocated for C members but it did not call C destructor thus leaving memory pointed by p_ allocated.
