error: Undefined Behavior: pointer arithmetic failed: ALLOC has size 4, so pointer to 1 byte starting at offset -1 is out-of-bounds --> RUSTLIB/core/src/ptr/const_ptr.rs:LL:CC | LL | unsafe { intrinsics::offset(self, count) } | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ pointer arithmetic failed: ALLOC has size 4, so pointer to 1 byte starting at offset -1 is out-of-bounds | = 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: backtrace: = note: inside `std::ptr::const_ptr::::offset` at RUSTLIB/core/src/ptr/const_ptr.rs:LL:CC note: inside `main` at $DIR/out_of_bounds_ptr_3.rs:LL:CC --> $DIR/out_of_bounds_ptr_3.rs:LL:CC | LL | let x = unsafe { x.offset(-1) }; | ^^^^^^^^^^^^ note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace error: aborting due to previous error