/in/foo.cc: In function 'int main()':
/in/foo.cc:8:12: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
  for(b=0;b=a;b+1)
            ^
/in/foo.cc:8:15: warning: for increment expression has no effect [-Wunused-value]
  for(b=0;b=a;b+1)
              ~^~