How bad is “if (!this)” in a C++ member function?

Question

If I come across old code that does if (!this) return; in an app, how severe a risk is this? Is it a dangerous ticking time bomb that requires an immediate app-wide

Answer 1

Future versions of the compiler are likely to more aggressively optimize in cases of formally undefined behavior. I wouldn't worry about existing deployments (where you know the behavior the compiler actually implemented), but it should be fixed in the source code in case you ever use a different compiler or different version.