macros are evil ! i want to set an item text in a listview control representing a date ListView_SetItemText(hWnd, iIndex, 1, log.GetTimeString().GetBuffer(0)); the log object is like this: class CLog : public CObject { ... CString GetDateString() { return m_datetime.Format(_T("%d/%m/%Y")); } CString GetTimeString() { return m_datetime.Format(_T("%H:%M:%S")); } ... } ListView_SetItemText(hWnd, iIndex, 1, log.GetTimeString().GetBuffer(0)); is bad because the CString object returned by the GetTimeString is temporary (and valid only in that line) but the ListView_SetItemtext is a macro ! looking inside it, it looks like this: #define ListView_SetItemText(hwndLV, i, iSubItem_, pszText_) { LV_ITEM _ms_lvi;_ms_lvi.iSubItem = iSubItem_;_ms_lvi.pszText = pszText_;SNDMSG((hwndLV), LVM_SETITEMTEXT, (WPARAM)(i), (LPARAM)(LV_ITEM *)&_ms_lvi);} so once the buffer is set to _ms_lvi.pszText the CString object is destroyed and the SNDMSG will send an invalid buffer