Peter Dimov wrote:
If the interface takes unsigned char, passing 322 will result in the function receiving 66. This may generate a compiler warning, or it may not. Even if it does generate a warning, an explicit static_cast to unsigned char (because the programmer thinks that the value is in range) will silence it.
I don't get it. I won't surprise anyone if I'll say that the whole point of xxx_cast is to signal the programmer who writes this code that he's doing something fishy, and he should carefully check if this is ok. The best thing a library writer can do, is to provide the maximum compiler checks that will produce either an error or a warning in case of suspicious usage. Forcing the user to use a red-flagged cast is exactly such an example. If the user chose to supress the warning using a cast, then we could only assume he knows what he's doing. Runtime checks are inferior because they A) hurt performance B) make code cumbersome so compile-time check are prefered. Was there anything new and surprising in what I just said? I think not...