simple_ref_fn/
ref_send_fn_mut.rs

1use crate::ref_fn_mut::RefFnMut;
2use crate::static_ref_mut_function::StaticRefMutFunction;
3
4/// A simple function wrapper that behaves like a [`&mut (dyn FnMut(T) -> R + Send)`](`FnMut`) type, but does not
5/// require a virtual table.
6pub struct RefSendFnMut<'a, T, R> {
7    inner: RefFnMut<'a, T, R>,
8}
9
10impl<'a, T, R> RefSendFnMut<'a, T, R> {
11    /// Create a [`RefSendFnMut`] object by binding [`F::call_mut`](`StaticRefMutFunction::call_mut`) function with
12    /// `data`.
13    pub fn new<F, D>(data: &'a mut D) -> Self
14    where
15        F: StaticRefMutFunction<'a, D, T, Output = R> + ?Sized,
16        D: Send,
17    {
18        Self {
19            inner: RefFnMut::new::<F, D>(data),
20        }
21    }
22
23    /// Create a [`RefSendFnMut`] object from a function reference.
24    pub fn from_fn_mut<F>(f: &'a mut F) -> Self
25    where
26        F: FnMut(T) -> R + Send,
27    {
28        Self::new::<F, F>(f)
29    }
30
31    /// Call the wrapped function.
32    pub fn call_mut(&mut self, arg: T) -> R {
33        self.inner.call_mut(arg)
34    }
35}
36
37impl<'a, F, T, R> From<&'a mut F> for RefSendFnMut<'a, T, R>
38where
39    F: FnMut(T) -> R + Send,
40{
41    fn from(value: &'a mut F) -> Self {
42        Self::from_fn_mut(value)
43    }
44}
45
46unsafe impl<T, R> Send for RefSendFnMut<'_, T, R> {}
47
48#[cfg(test)]
49mod tests {
50    use super::RefSendFnMut;
51    use crate::static_ref_mut_function::StaticRefMutFunction;
52
53    static_assertions::assert_impl_all!(RefSendFnMut<'static, (), ()>: From<&'static mut fn(())>, Send, Sync);
54
55    #[test]
56    fn test_ref_send_fn_mut_new() {
57        struct F;
58
59        impl StaticRefMutFunction<'_, u32, u32> for F {
60            type Output = u32;
61
62            fn call_mut(data: &mut u32, arg: u32) -> Self::Output {
63                let old_value = *data;
64
65                *data += arg;
66
67                old_value
68            }
69        }
70
71        let mut data = 2;
72        let mut f: RefSendFnMut<u32, u32> = F::bind_send(&mut data);
73
74        assert_eq!(f.call_mut(3), 2);
75        assert_eq!(f.call_mut(5), 5);
76        assert_eq!(f.call_mut(7), 10);
77
78        assert_eq!(data, 17);
79    }
80
81    #[test]
82    fn test_ref_send_fn_mut_from() {
83        let mut data = 2_u32;
84
85        let mut closure = |arg: u32| {
86            let old_value = data;
87
88            data += arg;
89
90            old_value
91        };
92
93        let mut f: RefSendFnMut<u32, u32> = RefSendFnMut::from(&mut closure);
94
95        assert_eq!(f.call_mut(3), 2);
96        assert_eq!(f.call_mut(5), 5);
97        assert_eq!(f.call_mut(7), 10);
98
99        assert_eq!(data, 17);
100    }
101}
simple_ref_fn/ref_send_fn_mut.rs

simple_ref_fn/
ref_send_fn_mut.rs
