Except the documentation you pointed to says... When the application is linked with a debug version of the C run-time libraries, _msize resolves to _msize__dbg So if the OP was linking to a debug version they would have got _msize_dbg
Except the documentation you pointed to says... When the application is linked with a debug version of the C run-time libraries, _msize resolves to _msize__dbg So if the OP was linking to a debug version they would have got _msize_dbg