What is the reason for precondition(condition:message:) to fail silently in release builds?

[SDGGiesbrecht (Jeremy David Giesbrecht)]

If it kept the message, what would be the difference between it and fatalError?

The way I understand it, precondition is intended as a compromise between assert and fatalError, where the compiler is allowed to optimize away everything related to constructing the message, but it won’t optimize away the check itself, so that the program is safe from spiraling into undefined territory.

For some examples of why someone would want to have the message stripped, see this thread:

We need `#fileName`

As I've been dusting off some proposals, I've realized something: #file is the wrong thing for us to be using to describe code context. We should be using #fileName instead. There are two main reasons that I've come up with to not use #file: using #file frequently bloats the size of your binary. Every #file usage results in a new StaticString value that has to get encoded into a __TEXT section of your binary. If your typical file-length path is 64 characters and you've got 128 paths in …