When should we use asserts in C?

Question

I am writing a function in C. As a matter of style, when is it good to use assert compared to returning an error code. Lets say the function is dividing two numbers. Should

Answer 1

Use an assert when your program meets a situation that does not allow to continue. Assertions are a 'contract' and I use them as a 'contract' with OS and situation 'danger in delay'.

In order to emulate exceptions you can still use GOTO 'ERRORLABEL' and terminate clean after running a clean up function.