Fumble fingers ... I meant oldval = *ptr++; -----Original Message----- From: gcc-help-owner@xxxxxxxxxxx [mailto:gcc-help-owner@xxxxxxxxxxx] On Behalf Of Jonathan Saxton Sent: Wednesday 19 May 2010 10:31 To: gcc-help Subject: RE: gcc compiler warnings Your compiler speaks the truth. You are not using the computed value. What do you think *ptr++; actually does? It fetches the value stored at *ptr, then increments ptr. Where do you use the value? As Andrew pointed out, perhaps you just wanted to increment the pointer without actually fetching the thing addressed by the pointer. If that is the case then you could just say: oldval = ptr++; // Make local copy and scroll 1 ahead in ring buffer -----Original Message----- From: gcc-help-owner@xxxxxxxxxxx [mailto:gcc-help-owner@xxxxxxxxxxx] On Behalf Of lee Sent: Wednesday 19 May 2010 05:42 To: gcc-help Subject: gcc compiler warnings Hi simple qeuery ... why does gcc give a warning: warning: value computed is not used for... ptr++; when the value is actually used! code segment... do { oldval=*ptr;//make local copy *ptr++; // scroll 1 ahead in ring buffer if(isHeader(&oldval) && cntnumber > 1 ) //skip first header word. check for header words inside data break; cntnumber += 1; }while( !isTrailer( &oldval ) && cntnumber < totalchannels ); // copy until the trailer Regards L
