gcc compiler warnings

[lee <funnyvoice@xxxxxxxxxxx>]

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