Enum Safety

impl Safety

fn parse_safe_or_unsafe(input: ParseStream<'_>) -> Result<Self>

Parses safe, unsafe, or default (neither).

This is appropriate for matching the syntax of extern blocks, in which functions are unsafe by default and require safe otherwise.

unsafe extern "C" {
    fn implicitly_unsafe();
    unsafe fn explicitly_unsafe();
    safe fn explicitly_safe();
}

fn parse_unsafe_only(input: ParseStream<'_>) -> Result<Self>

Parses unsafe or default (nothing).

This is appropriate for functions not within an extern block, which are safe by default and cannot be explicitly marked safe.

fn implicitly_safe() {}
unsafe fn explicitly_unsafe() {}

// safe fn explicitly_safe() {}
// ^^^^ ERROR: items outside of `unsafe extern { }` cannot be declared with `safe` safety qualifier