Versions of _strdup and _wcsdup that use the debug version of malloc.
char *_strdup_dbg( const char *strSource, int blockType, const char *filename, int linenumber ); wchar_t *_wcsdup_dbg( const wchar_t *strSource, int blockType, const char *filename, int linenumber );
The _strdup_dbg and _wcsdup_dbg functions are identical to _strdup and _wcsdup except that, when _DEBUG is defined, these functions use the debug version of malloc, _malloc_dbg, to allocate memory for the duplicated string. For information on the debugging features of _malloc_dbg, see _malloc_dbg.
You do not need to call these functions explicitly in most cases. Instead, you can define the flag _CRTDBG_MAP_ALLOC. When _CRTDBG_MAP_ALLOC is defined, calls to _strdup and _wcsdup are remapped to _strdup_dbg and _wcsdup_dbg, respectively, with the blockType set to _NORMAL_BLOCK. Thus, you do not need to call these functions explicitly unless you want to mark the heap blocks as _CLIENT_BLOCK. For more information on block types, see Types of Blocks on the Debug Heap.
_UNICODE & _MBCS not defined