[asveikau]

An assert is not guaranteed to terminate the process. In C, the most common implementation choice is to completely omit the check if you're not building in debug mode.

[uecker]

You need to turn it off by defining NDEBUG. While sometimes it is not for release builds, I am not sure this is common.

[asveikau]

Visual Studio defaults to defining NDEBUG in release mode, and I think that default was pretty influential