Pointer Provenance in Rust vs C++

Rust and C++ compilers track pointer provenance—the allocation each pointer derives from—as a compiler abstraction rather than a stored field, enabling optimizations such as Clang's -O2 reduction of a function to `return 1` when an opaque call cannot be shown to modify a local. The article uses LLVM IR to inspect this hidden provenance, noting exceptions like the CHERI architecture where provenance is hardware-enforced. The piece frames provenance as an obscure but crucial concept for developers reasoning about memory safety and compiler behavior. What to watch next: how the author's LLVM IR inspection of passing `&x` to an opaque function reveals where provenance assumptions surface in optimized code.