1//! Conversion between units of time.
2
3use self::sealed::Per;
4
5mod sealed {
6 /// A trait for defining the ratio of two units of time.
7 ///
8 /// This trait is used to implement the `per` method on the various structs.
9 pub trait Per<T> {
10 /// The smallest unsigned integer type that can represent [`VALUE`](Self::VALUE).
11 type Output;
12
13 /// The number of one unit of time in the other.
14 const VALUE: Self::Output;
15 }
16}
17
18/// Declare and implement `Per` for all relevant types. Identity implementations are automatic.
19macro_rules! impl_per {
20 ($($t:ident ($str:literal) per {$(
21 $larger:ident : $output:ty = $value:expr
22 )*})*) => {$(
23 #[doc = concat!("A unit of time representing exactly one ", $str, ".")]
24 #[derive(Debug, Clone, Copy)]
25 pub struct $t;
26
27 impl $t {
28 #[doc = concat!("Obtain the number of times `", stringify!($t), "` can fit into `T`.")]
29 #[doc = concat!("If `T` is smaller than `", stringify!($t), "`, the code will fail to")]
30 /// compile. The return type is the smallest unsigned integer type that can represent
31 /// the value.
32 ///
33 /// Valid calls:
34 ///
35 #[doc = concat!(" - `", stringify!($t), "::per(", stringify!($t), ")` (returns `u8`)")]
36 $(#[doc = concat!(" - `", stringify!($t), "::per(", stringify!($larger), ")` (returns `", stringify!($output), "`)")])*
37 pub const fn per<T>(_larger: T) -> <Self as Per<T>>::Output
38 where
39 Self: Per<T>,
40 T: Copy,
41 {
42 Self::VALUE
43 }
44 }
45
46 impl Per<$t> for $t {
47 type Output = u8;
48
49 const VALUE: u8 = 1;
50 }
51
52 $(impl Per<$larger> for $t {
53 type Output = $output;
54
55 const VALUE: $output = $value;
56 })*
57 )*};
58}
59
60impl_per! {
61 Nanosecond ("nanosecond") per {
62 Microsecond: u16 = 1_000
63 Millisecond: u32 = 1_000_000
64 Second: u32 = 1_000_000_000
65 Minute: u64 = 60_000_000_000
66 Hour: u64 = 3_600_000_000_000
67 Day: u64 = 86_400_000_000_000
68 Week: u64 = 604_800_000_000_000
69 }
70 Microsecond ("microsecond") per {
71 Millisecond: u16 = 1_000
72 Second: u32 = 1_000_000
73 Minute: u32 = 60_000_000
74 Hour: u32 = 3_600_000_000
75 Day: u64 = 86_400_000_000
76 Week: u64 = 604_800_000_000
77 }
78 Millisecond ("millisecond") per {
79 Second: u16 = 1_000
80 Minute: u16 = 60_000
81 Hour: u32 = 3_600_000
82 Day: u32 = 86_400_000
83 Week: u32 = 604_800_000
84 }
85 Second ("second") per {
86 Minute: u8 = 60
87 Hour: u16 = 3_600
88 Day: u32 = 86_400
89 Week: u32 = 604_800
90 }
91 Minute ("minute") per {
92 Hour: u8 = 60
93 Day: u16 = 1_440
94 Week: u16 = 10_080
95 }
96 Hour ("hour") per {
97 Day: u8 = 24
98 Week: u8 = 168
99 }
100 Day ("day") per {
101 Week: u8 = 7
102 }
103 Week ("week") per {}
104}
105