src/test/ui/lint/opaque-ty-ffi-unsafe.rs

   1 // revisions: min_tait full_tait
   2 #![feature(min_type_alias_impl_trait)]
   3 #![cfg_attr(full_tait, feature(type_alias_impl_trait))]
   4 //[full_tait]~^ WARN incomplete
   5 #![deny(improper_ctypes)]
   6
   7 type A = impl Fn();
   8
   9 pub fn ret_closure() -> A {
  10     || {}
  11 }
  12
  13 extern "C" {
  14     pub fn a(_: A);
  15 //~^ ERROR `extern` block uses type `impl Fn<()>`, which is not FFI-safe
  16 }
  17
  18 fn main() {}