extend_mut 0.4.4

A library for extending exclusive references.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164

/*!

This module contains implementations for helper traits

IntoExtendMutReturn:
No impl for IntoExtendMutReturn<(&mut T, &mut T), ()>
*/

use crate::{ExtendMut, IntoExtendMutReturn, extend_mut};

#[cfg(feature = "assume-non-forget")]
use crate::extend_mut_async;

// #![feature(generic_const_exprs)]
// trait NotZst: Sized {}
// impl<T> NotZst for T where [(); size_of::<T>() - 1]: Sized {}

macro_rules! impl_into_extend_mut {
    (unit: $head:ident,) => {
        unsafe impl<'a, $head: ?Sized> IntoExtendMutReturn<(&'a mut $head,), ()> for (&'a mut $head,) {
            #[inline(always)]
            fn into_extend_mut_return(self) -> ((&'a mut $head,), ()) { (self, ()) }
        }
    };
    (unit: $head:ident, $($param:ident,)*) => {
        unsafe impl<'a, $head: ?Sized, $($param,)*> IntoExtendMutReturn<(&'a mut $head, $(&'a mut $param,)*), ()>
            for (&'a mut $head, $(&'a mut $param,)*)
        {
            #[inline(always)]
            fn into_extend_mut_return(self) -> ((&'a mut $head, $(&'a mut $param,)*), ()) { (self, ()) }
        }
        impl_into_extend_mut!(unit: $($param,)*);
    };
    (any: $head:ident,) => {
        unsafe impl<'a, $head: ?Sized, R> IntoExtendMutReturn<(&'a mut $head,), R> for ((&'a mut $head,), R) {
            #[inline(always)]
            fn into_extend_mut_return(self) -> ((&'a mut $head,), R) { self }
        }
    };
    (any: $head:ident, $($param:ident,)*) => {
        unsafe impl<'a, $head: ?Sized, $($param: ?Sized,)* R> IntoExtendMutReturn<(&'a mut $head, $(&'a mut $param,)*), R>
            for ((&'a mut $head, $(&'a mut $param,)*), R)
        {
            #[inline(always)]
            fn into_extend_mut_return(self) -> ((&'a mut $head, $(&'a mut $param,)*), R) { self }
        }
        impl_into_extend_mut!(any: $($param,)*);
    };
}

macro_rules! impl_extend_mut_many {
    ($head:ident,) => {
        #[allow(non_snake_case)]
        impl<'a, 'b, $head: ?Sized + 'b> ExtendMut<'b> for (&'a mut $head,) {
            type Extended = (&'b mut $head,);
            #[inline(always)]
            fn extend_mut<R, ER: IntoExtendMutReturn<Self::Extended, R>>(
                self,
                f: impl FnOnce(Self::Extended) -> ER,
            ) -> R {
                extend_mut(self.0, #[inline(always)] |x| {
                    let ((x,), r) = f((x,)).into_extend_mut_return();
                    (x, r)
                })
            }
            #[cfg(feature = "assume-non-forget")]
            #[inline(always)]
            async fn extend_mut_async<R, ER: IntoExtendMutReturn<Self::Extended, R>>(
                self,
                f: impl AsyncFnOnce(Self::Extended) -> ER,
            ) -> R {
                extend_mut_async(self.0, #[inline(always)] async |x| {
                    let ((x,), r) = f((x,)).await.into_extend_mut_return();
                    (x, r)
                }).await
            }
        }
    };
    ($head:ident, $($param:ident,)*) => {
        #[allow(non_snake_case)]
        impl <'a, 'b, $head: ?Sized + 'b, $($param: ?Sized + 'b,)*> ExtendMut<'b> for (&'a mut $head, $(&'a mut $param,)*) {
            type Extended = (&'b mut $head, $(&'b mut $param,)*);
            #[inline(always)]
            fn extend_mut<R, ER: IntoExtendMutReturn<Self::Extended, R>>( self, f: impl FnOnce(Self::Extended) -> ER,) -> R {
                let (x, $($param,)*) = self;
                extend_mut(x, #[inline(always)] |x| {
                    ($($param,)*).extend_mut(#[inline(always)] |($($param,)*)| {
                        let ((x, $($param,)*), r) = f((x, $($param,)*)).into_extend_mut_return();
                        (($($param,)*), (x, r))
                    })
                })
            }
            #[cfg(feature = "assume-non-forget")]
            #[inline(always)]
            async fn extend_mut_async<R, ER: IntoExtendMutReturn<Self::Extended, R>>( self, f: impl AsyncFnOnce(Self::Extended) -> ER,) -> R {
                let (x, $($param,)*) = self;
                extend_mut_async(x, #[inline(always)] async |x| {
                    ($($param,)*).extend_mut_async(#[inline(always)] async |($($param,)*)| {
                        let ((x, $($param,)*), r) = f((x, $($param,)*)).await.into_extend_mut_return();
                        (($($param,)*), (x, r))
                    }).await
                }).await
            }
        }
        impl_extend_mut_many!($($param,)*);
    };
}

unsafe impl<'a, T: ?Sized, R> IntoExtendMutReturn<&'a mut T, R> for (&'a mut T, R) {
    #[inline(always)]
    fn into_extend_mut_return(self) -> (&'a mut T, R) {
        self
    }
}

unsafe impl<'a, T: ?Sized> IntoExtendMutReturn<&'a mut T, ()> for &'a mut T {
    #[inline(always)]
    fn into_extend_mut_return(self) -> (&'a mut T, ()) {
        (self, ())
    }
}

impl_into_extend_mut!(any: T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,);
impl_into_extend_mut!(unit: T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,);

impl<'a, 'b, T: ?Sized + 'b> ExtendMut<'b> for &'a mut T {
    type Extended = &'b mut T;
    #[inline(always)]
    fn extend_mut<R, ER: IntoExtendMutReturn<Self::Extended, R>>(
        self,
        f: impl FnOnce(Self::Extended) -> ER,
    ) -> R {
        extend_mut(self, f)
    }
    #[cfg(feature = "assume-non-forget")]
    #[inline(always)]
    async fn extend_mut_async<R, ER: IntoExtendMutReturn<Self::Extended, R>>(
        self,
        f: impl AsyncFnOnce(Self::Extended) -> ER,
    ) -> R {
        extend_mut_async(self, f).await
    }
}

impl<'b> ExtendMut<'b> for () {
    type Extended = ();
    #[inline(always)]
    fn extend_mut<R, ER: IntoExtendMutReturn<Self::Extended, R>>(
        self,
        f: impl FnOnce(Self::Extended) -> ER,
    ) -> R {
        f(()).into_extend_mut_return().1
    }
    #[cfg(feature = "assume-non-forget")]
    #[inline(always)]
    async fn extend_mut_async<R, ER: IntoExtendMutReturn<Self::Extended, R>>(
        self,
        f: impl AsyncFnOnce(Self::Extended) -> ER,
    ) -> R {
        f(()).await.into_extend_mut_return().1
    }
}

impl_extend_mut_many!(T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13,);