diff options
Diffstat (limited to 'rust/qemu-api/src/callbacks.rs')
| -rw-r--r-- | rust/qemu-api/src/callbacks.rs | 27 |
1 files changed, 1 insertions, 26 deletions
diff --git a/rust/qemu-api/src/callbacks.rs b/rust/qemu-api/src/callbacks.rs index 9642a16eb8..dbe2305f50 100644 --- a/rust/qemu-api/src/callbacks.rs +++ b/rust/qemu-api/src/callbacks.rs @@ -113,31 +113,6 @@ use std::{mem, ptr::NonNull}; /// This is always true for zero-capture closures and function pointers, as long /// as the code is able to name the function in the first place. pub unsafe trait FnCall<Args, R = ()>: 'static + Sync + Sized { - /// Referring to this internal constant asserts that the `Self` type is - /// zero-sized. Can be replaced by an inline const expression in - /// Rust 1.79.0+. - const ASSERT_ZERO_SIZED: () = { assert!(mem::size_of::<Self>() == 0) }; - - /// Referring to this constant asserts that the `Self` type is an actual - /// function type, which can be used to catch incorrect use of `()` - /// at compile time. - /// - /// # Examples - /// - /// ```compile_fail - /// # use qemu_api::callbacks::FnCall; - /// fn call_it<F: for<'a> FnCall<(&'a str,), String>>(_f: &F, s: &str) -> String { - /// let _: () = F::ASSERT_IS_SOME; - /// F::call((s,)) - /// } - /// - /// let s: String = call_it((), "hello world"); // does not compile - /// ``` - /// - /// Note that this can be more simply `const { assert!(F::IS_SOME) }` in - /// Rust 1.79.0 or newer. - const ASSERT_IS_SOME: () = { assert!(Self::IS_SOME) }; - /// `true` if `Self` is an actual function type and not `()`. /// /// # Examples @@ -195,7 +170,7 @@ macro_rules! impl_call { #[inline(always)] fn call(a: ($($args,)*)) -> R { - let _: () = Self::ASSERT_ZERO_SIZED; + const { assert!(mem::size_of::<Self>() == 0) }; // SAFETY: the safety of this method is the condition for implementing // `FnCall`. As to the `NonNull` idiom to create a zero-sized type, |