Unsafe blocks
unsafe { } marks a block as explicitly unchecked, primarily as a code-intent signal.
Summary
At the moment, unsafe is a parsing and AST annotation. The runtime does not restrict what happens inside it. Its value is communicating to readers and future tooling that the enclosed code is intentionally outside normal safety guarantees, such as FFI calls or low-level buffer manipulation.
Canonical
unsafe { } marks a block as unchecked. Currently a parsing/AST annotation: the runtime doesn't restrict anything inside unsafe blocks, but it signals intent to the reader and to future tooling.
unsafe {
-- code that does something risky
let ptr = some_ffi_call()
}