error: Undefined Behavior: type validation failed: encountered (potentially part of) a pointer, but expected plain (non-pointer) bytes
  --> $DIR/branchless-select-i128-pointer.rs:LL:CC
   |
LL |                 !mask & transmute::<_, TwoPtrs>("false !") | mask & transmute::<_, TwoPtrs>("true !"),
   |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered (potentially part of) a pointer, but expected plain (non-pointer) bytes
   |
   = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
   = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
           
   = note: inside `main` at $DIR/branchless-select-i128-pointer.rs:LL:CC

note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace

error: aborting due to previous error