Convert a zero-sized closure into an `extern "C" fn(…)` pointer
APACHE-2.0 License
::extern-c
Convert a zero-sized closure into an extern "C" fn()
pointer with the
same[^abi] type signature.
[^abi]: but for the ABI, of course!
use ::extern_c::extern_c;
let f: extern "C" fn(bool) -> u8 = extern_c(|b: bool| b as u8);
assert_eq!(f(true), 1);