deep_time/dt/
helpers.rs

1use crate::{ATTOS_PER_SEC_I128, ATTOS_PER_SECF, Dt, Real};
2
3impl Dt {
4    /// Clamps an `i128` to the representable range of `i64`.
5    pub const fn to_i64(x: i128) -> i64 {
6        let y = x as i64;
7        if x == y as i128 {
8            y
9        } else if x > 0 {
10            i64::MAX
11        } else {
12            i64::MIN
13        }
14    }
15
16    /// Clamps an `i128` to the representable range of `u64`.
17    pub const fn to_u64(x: i128) -> u64 {
18        if x > u64::MAX as i128 {
19            u64::MAX
20        } else if x < u64::MIN as i128 {
21            u64::MIN
22        } else {
23            x as u64
24        }
25    }
26
27    /// Combines a whole unit count and fractional attoseconds within that unit into total attoseconds.
28    ///
29    /// Computes `whole * unit_attos + frac_attos`. The fractional part is always **added**, even
30    /// when `whole` is negative — the Euclidean / floor split used by
31    /// [`to_ms_floor`](../struct.Dt.html#method.to_ms_floor),
32    /// [`to_ns_floor`](../struct.Dt.html#method.to_ns_floor), and related methods, and by
33    /// constructors such as
34    /// [`from_ms_floor`](../struct.Dt.html#method.from_ms_floor) and
35    /// [`from_ns_floor`](../struct.Dt.html#method.from_ns_floor).
36    ///
37    /// This is **not** the same as pairing with truncating extractors like
38    /// [`to_ms`](../struct.Dt.html#method.to_ms) (signed remainder). Unlike
39    /// [`from_sec_and_frac`](../struct.Dt.html#method.from_sec_and_frac), the fraction is never
40    /// subtracted when `whole` is negative.
41    #[inline(always)]
42    pub const fn unit_and_attos_to_attos(whole: i128, frac_attos: u128, unit_attos: i128) -> i128 {
43        whole
44            .saturating_mul(unit_attos)
45            .saturating_add(frac_attos as i128)
46    }
47
48    /// Converts seconds i128 → total attoseconds i128
49    #[inline(always)]
50    pub const fn sec_to_attos(sec: i128) -> i128 {
51        sec.saturating_mul(ATTOS_PER_SEC_I128)
52    }
53
54    /// Converts total attoseconds → whole seconds as i64
55    #[inline(always)]
56    pub const fn attos_to_sec_i64(attos: i128) -> i64 {
57        Self::to_i64(attos / ATTOS_PER_SEC_I128)
58    }
59
60    /// Clamps `value` to the range `[min, max]`.
61    ///
62    /// This is a `const fn`, so it can be used in const contexts
63    /// (e.g. const generics, statics, const evaluation, etc.).
64    ///
65    /// If `min > max`, the result is equivalent to clamping to `[max, min]`.
66    pub const fn clamp_u8(value: u8, min: u8, max: u8) -> u8 {
67        if value < min {
68            min
69        } else if value > max {
70            max
71        } else {
72            value
73        }
74    }
75
76    /// Clamps `value` to the range `[min, max]`.
77    ///
78    /// This is a `const fn`, so it can be used in const contexts
79    /// (e.g. const generics, statics, const evaluation, etc.).
80    ///
81    /// If `min > max`, the result is equivalent to clamping to `[max, min]`.
82    pub const fn clamp_u64(value: u64, min: u64, max: u64) -> u64 {
83        if value < min {
84            min
85        } else if value > max {
86            max
87        } else {
88            value
89        }
90    }
91
92    /// **Lossy** conversion of u128 attoseconds to → float seconds (s).
93    #[inline(always)]
94    pub const fn attos_to_sec_f(attos: u128) -> Real {
95        f!(attos) / ATTOS_PER_SECF
96    }
97}
deep_time/dt/helpers.rs

deep_time/dt/
helpers.rs
