oxedyne/fe2o3 — fe2o3

1.6 KiB, 6 runs

created by r1870400018:633, which is this file's identity for as long as the history lasts, whatever it is later renamed to

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1	use oxedyne_fe2o3_core::prelude::*;
2
3	use std::string;
4
5	pub trait PrimInt: Sized + string::ToString {
6	fn is_neg(self) -> bool;
7	}
8
9	impl PrimInt for u8 {
10	fn is_neg(self) -> bool { false }
11	}
12
13	impl PrimInt for i8 {
14	fn is_neg(self) -> bool { self < 0 }
15	}
16
17	impl PrimInt for u16 {
18	fn is_neg(self) -> bool { false }
19	}
20
21	impl PrimInt for i16 {
22	fn is_neg(self) -> bool { self < 0 }
23	}
24
25	impl PrimInt for u32 {
26	fn is_neg(self) -> bool { false }
27	}
28
29	impl PrimInt for i32 {
30	fn is_neg(self) -> bool { self < 0 }
31	}
32
33	impl PrimInt for u64 {
34	fn is_neg(self) -> bool { false }
35	}
36
37	impl PrimInt for i64 {
38	fn is_neg(self) -> bool { self < 0 }
39	}
40
41	impl PrimInt for usize {
42	fn is_neg(self) -> bool { false }
43	}
44
45	impl PrimInt for isize {
46	fn is_neg(self) -> bool { self < 0 }
47	}
48
49	pub trait Signed {}
50	pub trait Unsigned {}
51
52	/// Fast `usize` ceiling division.
53	/// Credit: https://stackoverflow.com/questions/2745074/fast-ceiling-of-an-integer-division-in-c-c
54	pub fn usize_ceil_div(dividend: usize, divisor: usize) -> Outcome<usize> {
55	if divisor == 0 {
56	Err(err!(
57	"Attempt to divide {} by {}, latter cannot be zero",
58	dividend, divisor;
59	Numeric, Input, Invalid))
60	} else if dividend == 0 {
61	Ok(0)
62	} else {
63	Ok(1 + ((dividend - 1) / divisor))
64	}
65	}
66
67	#[cfg(test)]
68	mod tests {
69	use super::*;
70
71	#[test]
72	fn test_ceiling_div_01() {
73	for x in 1..1000 {
74	for y in 1..x {
75	let xf = x as f64;
76	let yf = y as f64;
77	let q = (xf/yf).ceil() as usize;
78	assert_eq!(q, usize_ceil_div(x, y).unwrap());
79	}
80	}
81	}
82	}