Ignoring warnings is a bad idea. At some level, we all know this. If we see a sign that says “Warning: Dangerous Undertow” at the beach, we pause (I hope!) and think twice before we get in the water.
Yet we sometimes get cavalier about warnings in software. Specifially, I have heard programmers describe compiler warnings as being less severe than errors–as if worrying about them is optional.
This is simply not true.