simple_ref_fn/
ref_sync_fn.rs

1use crate::ref_fn::RefFn;
2use crate::static_ref_function::StaticRefFunction;
3
4/// A simple function wrapper that behaves like a [`&(dyn Fn(T) -> R + Sync)`](`Fn`) type, but does not require a
5/// virtual table.
6pub struct RefSyncFn<'a, T, R> {
7    inner: RefFn<'a, T, R>,
8}
9
10impl<'a, T, R> RefSyncFn<'a, T, R> {
11    /// Create a [`RefSyncFn`] object by binding [`F::call`](`StaticRefFunction::call`) function with `data`.
12    pub fn new<F, D>(data: &'a D) -> Self
13    where
14        F: StaticRefFunction<'a, D, T, Output = R> + ?Sized,
15        D: Sync,
16    {
17        Self {
18            inner: RefFn::new::<F, D>(data),
19        }
20    }
21
22    /// Create a [`RefSyncFn`] object from a function reference.
23    pub fn from_fn<F>(f: &'a F) -> Self
24    where
25        F: Fn(T) -> R + Sync,
26    {
27        Self::new::<F, F>(f)
28    }
29
30    /// Call the wrapped function.
31    pub fn call(&self, arg: T) -> R {
32        self.inner.call(arg)
33    }
34}
35
36impl<T, R> Clone for RefSyncFn<'_, T, R> {
37    fn clone(&self) -> Self {
38        *self
39    }
40}
41
42impl<T, R> Copy for RefSyncFn<'_, T, R> {}
43
44impl<'a, F, T, R> From<&'a F> for RefSyncFn<'a, T, R>
45where
46    F: Fn(T) -> R + Sync,
47{
48    fn from(value: &'a F) -> Self {
49        Self::from_fn(value)
50    }
51}
52
53unsafe impl<T, R> Send for RefSyncFn<'_, T, R> {}
54unsafe impl<T, R> Sync for RefSyncFn<'_, T, R> {}
55
56#[cfg(test)]
57mod tests {
58    use super::RefSyncFn;
59    use crate::static_ref_function::StaticRefFunction;
60
61    static_assertions::assert_impl_all!(RefSyncFn<'static, (), ()>: Clone, Copy, From<&'static fn(())>, Send, Sync);
62
63    #[test]
64    fn test_ref_sync_fn_new() {
65        struct F;
66
67        impl StaticRefFunction<'_, u32, u32> for F {
68            type Output = u32;
69
70            fn call(data: &u32, arg: u32) -> Self::Output {
71                data + arg
72            }
73        }
74
75        let data = 2;
76        let f: RefSyncFn<u32, u32> = F::bind_sync(&data);
77
78        assert_eq!(f.call(3), 5);
79        assert_eq!(f.call(5), 7);
80        assert_eq!(f.call(7), 9);
81    }
82
83    #[test]
84    fn test_ref_sync_fn_from() {
85        let data = 2_u32;
86        let closure = |arg: u32| data + arg;
87        let f: RefSyncFn<u32, u32> = RefSyncFn::from(&closure);
88
89        assert_eq!(f.call(3), 5);
90        assert_eq!(f.call(5), 7);
91        assert_eq!(f.call(7), 9);
92    }
93}
simple_ref_fn/ref_sync_fn.rs

simple_ref_fn/
ref_sync_fn.rs
