petgraph/
macros.rs

1macro_rules! clone_fields {
2    ($name:ident, $($field:ident),+ $(,)*) => (
3        fn clone(&self) -> Self {
4            $name {
5                $(
6                    $field : self . $field .clone()
7                ),*
8            }
9        }
10    );
11}
12
13macro_rules! iterator_wrap {
14    (impl () for
15    struct $name: ident <$($typarm:tt),*> where { $($bounds: tt)* }
16     item: $item: ty,
17     iter: $iter: ty,
18     ) => ();
19    (
20    impl (Iterator $($rest:tt)*)  for
21    $(#[$derive:meta])*
22     struct $name: ident <$($typarm:tt),*> where { $($bounds: tt)* }
23     item: $item: ty,
24     iter: $iter: ty,
25     ) => (
26        // having complex iterator types is kind of the point of this macro
27        #[allow(clippy::type_complexity)]
28        $(#[$derive])*
29        pub struct $name <$($typarm),*> where $($bounds)* {
30            iter: $iter,
31        }
32        impl<$($typarm),*> Iterator for $name <$($typarm),*>
33            where $($bounds)*
34        {
35            type Item = $item;
36            #[inline]
37            fn next(&mut self) -> Option<Self::Item> {
38                self.iter.next()
39            }
40
41            #[inline]
42            fn size_hint(&self) -> (usize, Option<usize>) {
43                self.iter.size_hint()
44            }
45        }
46        iterator_wrap!(
47            impl ($($rest)*)  for
48            struct $name <$($typarm),*> where { $($bounds)* }
49            item: $item,
50            iter: $iter,
51            );
52        );
53
54    (
55impl (ExactSizeIterator $($rest:tt)*)  for
56    $(#[$derive:meta])*
57     struct $name: ident <$($typarm:tt),*> where { $($bounds: tt)* }
58     item: $item: ty,
59     iter: $iter: ty,
60     ) => (
61        impl<$($typarm),*> ExactSizeIterator for $name <$($typarm),*>
62            where $($bounds)*
63        {
64            #[inline]
65            fn len(&self) -> usize {
66                self.iter.len()
67            }
68        }
69        iterator_wrap!(
70            impl ($($rest)*)  for
71         $(#[$derive])*
72            struct $name <$($typarm),*> where { $($bounds)* }
73            item: $item,
74            iter: $iter,
75            );
76    );
77
78    (
79impl (DoubleEndedIterator $($rest:tt)*)  for
80    $(#[$derive:meta])*
81     struct $name: ident <$($typarm:tt),*> where { $($bounds: tt)* }
82     item: $item: ty,
83     iter: $iter: ty,
84     ) => (
85        impl<$($typarm),*> DoubleEndedIterator for $name <$($typarm),*>
86            where $($bounds)*
87        {
88            fn next_back(&mut self) -> Option<Self::Item> {
89                self.iter.next_back()
90            }
91            fn rfold<B, F>(self, accum: B, f: F) -> B
92                where
93                    F: FnMut(B, Self::Item) -> B,
94                { self.iter.rfold(accum, f) }
95            fn rfind<P>(&mut self, predicate: P) -> Option<Self::Item>
96                where
97                    P: FnMut(&Self::Item) -> bool,
98                { self.iter.rfind(predicate) }
99        }
100        iterator_wrap!(
101            impl ($($rest)*)  for
102         $(#[$derive])*
103           struct $name <$($typarm),*> where { $($bounds)* }
104            item: $item,
105            iter: $iter,
106            );
107    );
108}
petgraph/macros.rs

petgraph/
macros.rs
