layer_rs/
markers.rs

1pub struct Zero;
2pub struct Succ<N>(std::marker::PhantomData<N>);
3
4pub trait Equal<N1, N2> {}
5impl Equal<Zero, Zero> for () {}
6impl<N1, N2> Equal<Succ<N1>, Succ<N2>> for () where (): Equal<N1, N2> {}
7
8pub trait IsNumber {}
9impl IsNumber for Zero {}
10impl<N> IsNumber for Succ<N> where N: IsNumber {}
11
12pub trait GreaterThanOrEqual<N1, N2> {}
13impl GreaterThanOrEqual<Zero, Zero> for () {}
14impl<N> GreaterThanOrEqual<Succ<N>, Zero> for () {}
15impl<N1, N2> GreaterThanOrEqual<Succ<N1>, Succ<N2>> for () where (): GreaterThanOrEqual<N1, N2> {}
16
17pub trait LessThan<N1, N2> {}
18impl<N> LessThan<Zero, Succ<N>> for () where N: IsNumber {}
19impl<N1, N2> LessThan<Succ<N1>, Succ<N2>> for () where (): LessThan<N1, N2> {}
20
21pub trait Max<N1, N2>
22where
23    N1: IsNumber,
24    N2: IsNumber,
25    Self::Output: IsNumber,
26{
27    type Output;
28}
29
30impl Max<Zero, Zero> for () {
31    type Output = Zero;
32}
33
34impl<N> Max<Succ<N>, Zero> for ()
35where
36    N: IsNumber,
37{
38    type Output = Succ<N>;
39}
40impl<N> Max<Zero, Succ<N>> for ()
41where
42    N: IsNumber,
43{
44    type Output = Succ<N>;
45}
46
47impl<N1, N2> Max<Succ<N1>, Succ<N2>> for ()
48where
49    N1: IsNumber,
50    N2: IsNumber,
51    (): Max<N1, N2>,
52{
53    type Output = Succ<<() as Max<N1, N2>>::Output>;
54}
55
56pub trait Min<N1, N2>
57where
58    N1: IsNumber,
59    N2: IsNumber,
60    Self::Output: IsNumber,
61{
62    type Output;
63}
64
65impl Min<Zero, Zero> for () {
66    type Output = Zero;
67}
68
69impl<N> Min<Succ<N>, Zero> for ()
70where
71    N: IsNumber,
72{
73    type Output = Zero;
74}
75impl<N> Min<Zero, Succ<N>> for ()
76where
77    N: IsNumber,
78{
79    type Output = Zero;
80}
81
82impl<N1, N2> Min<Succ<N1>, Succ<N2>> for ()
83where
84    N1: IsNumber,
85    N2: IsNumber,
86    (): Min<N1, N2>,
87{
88    type Output = Succ<<() as Min<N1, N2>>::Output>;
89}
90
91pub struct Here;
92pub struct Left<PrevDirection>(std::marker::PhantomData<PrevDirection>);
93pub struct Right<PrevDirection>(std::marker::PhantomData<PrevDirection>);
layer_rs/markers.rs

layer_rs/
markers.rs
