Spec on casting to integer with smaller range than value

[kinke]

On Saturday, 28 March 2020 at 15:47:04 UTC, Dennis wrote:
> Which would make `cast(int) someFloat` not allowed in @safe 
> code.

In LLVM lingo, the out-of-bounds cast wouldn't be undefined 
behavior per se, but yield a 'poison' value, whose later usage 
might eventually trigger undefined behavior, depending on what 
exactly you're doing with it.

> Safe functions are functions that are statically checked to 
> exhibit no possibility of undefined behavior.

If that's really the ultimate goal, then these casts would 
probably need a prefixed bounds check in @safe code, just like an 
array bounds check (incl. omitting it if it can be statically 
determined to fit).