How to enable warning about unsafe implicit casting?

Question

C++ / C#

I'm used to the fact that in Java, when overflowing (with the exception of an increment), an error occurs, and in C ++ the compiler does not even warn (only if the overflow is a literal). Is it possible to enable the compiler to notify about an unsafe cast?

Answer 1

0) Such errors occur at runtime, that is, when the application is running.
1) When the application is running, the compiler is no longer involved.
2) C++ handles all these errors, only it needs to be programmed