Securely clear secrets from memory with a simple trait built on stable Rust primitives which guarantee they will be zeroed out using an operation will not be 'optimized away' by the compiler. Uses a portable implementation that leverages LLVM's volatile write semantics and memory fences. No weird tricks, no FFI/ASM, no insecure fallbacks, no dependencies, no std, just a trait implemented for all of Rust's core scalar types and slices/iterators thereof for securely zeroing memory.