1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! Numeric traits and functions for generic mathematics
13 //! These are implemented for the primitive numeric types in `std::{u8, u16,
14 //! u32, u64, uint, i8, i16, i32, i64, int, f32, f64}`.
16 #![allow(missing_doc)]
21 #[cfg(test)] use fmt::Show;
23 pub use core::num::{Num, div_rem, Zero, zero, One, one};
24 pub use core::num::{Signed, abs, abs_sub, signum};
25 pub use core::num::{Unsigned, pow, Bounded};
26 pub use core::num::{Primitive, Int, Saturating};
27 pub use core::num::{CheckedAdd, CheckedSub, CheckedMul, CheckedDiv};
28 pub use core::num::{cast, FromPrimitive, NumCast, ToPrimitive};
29 pub use core::num::{next_power_of_two, is_power_of_two};
30 pub use core::num::{checked_next_power_of_two};
31 pub use core::num::{from_int, from_i8, from_i16, from_i32, from_i64};
32 pub use core::num::{from_uint, from_u8, from_u16, from_u32, from_u64};
33 pub use core::num::{from_f32, from_f64};
34 pub use core::num::{FPCategory, FPNaN, FPInfinite, FPZero, FPSubnormal};
35 pub use core::num::{FPNormal, Float};
39 /// Mathematical operations on primitive floating point numbers.
40 pub trait FloatMath: Float {
41 /// Constructs a floating point number created by multiplying `x` by 2
42 /// raised to the power of `exp`.
43 fn ldexp(x: Self, exp: int) -> Self;
44 /// Breaks the number into a normalized fraction and a base-2 exponent,
47 /// * `self = x * pow(2, exp)`
49 /// * `0.5 <= abs(x) < 1.0`
50 fn frexp(self) -> (Self, int);
52 /// Returns the next representable floating-point value in the direction of
54 fn next_after(self, other: Self) -> Self;
56 /// Returns the maximum of the two numbers.
57 fn max(self, other: Self) -> Self;
58 /// Returns the minimum of the two numbers.
59 fn min(self, other: Self) -> Self;
61 /// Take the cubic root of a number.
62 fn cbrt(self) -> Self;
63 /// Calculate the length of the hypotenuse of a right-angle triangle given
64 /// legs of length `x` and `y`.
65 fn hypot(self, other: Self) -> Self;
67 /// Computes the sine of a number (in radians).
69 /// Computes the cosine of a number (in radians).
71 /// Computes the tangent of a number (in radians).
74 /// Computes the arcsine of a number. Return value is in radians in
75 /// the range [-pi/2, pi/2] or NaN if the number is outside the range
77 fn asin(self) -> Self;
78 /// Computes the arccosine of a number. Return value is in radians in
79 /// the range [0, pi] or NaN if the number is outside the range
81 fn acos(self) -> Self;
82 /// Computes the arctangent of a number. Return value is in radians in the
83 /// range [-pi/2, pi/2];
84 fn atan(self) -> Self;
85 /// Computes the four quadrant arctangent of a number, `y`, and another
86 /// number `x`. Return value is in radians in the range [-pi, pi].
87 fn atan2(self, other: Self) -> Self;
88 /// Simultaneously computes the sine and cosine of the number, `x`. Returns
89 /// `(sin(x), cos(x))`.
90 fn sin_cos(self) -> (Self, Self);
92 /// Returns the exponential of the number, minus 1, in a way that is
93 /// accurate even if the number is close to zero.
94 fn exp_m1(self) -> Self;
95 /// Returns the natural logarithm of the number plus 1 (`ln(1+n)`) more
96 /// accurately than if the operations were performed separately.
97 fn ln_1p(self) -> Self;
99 /// Hyperbolic sine function.
100 fn sinh(self) -> Self;
101 /// Hyperbolic cosine function.
102 fn cosh(self) -> Self;
103 /// Hyperbolic tangent function.
104 fn tanh(self) -> Self;
105 /// Inverse hyperbolic sine function.
106 fn asinh(self) -> Self;
107 /// Inverse hyperbolic cosine function.
108 fn acosh(self) -> Self;
109 /// Inverse hyperbolic tangent function.
110 fn atanh(self) -> Self;
113 /// A generic trait for converting a value to a string with a radix (base)
114 pub trait ToStrRadix {
115 fn to_str_radix(&self, radix: uint) -> String;
118 /// A generic trait for converting a string with a radix (base) to a value
119 pub trait FromStrRadix {
120 fn from_str_radix(str: &str, radix: uint) -> Option<Self>;
123 /// A utility function that just calls FromStrRadix::from_str_radix.
124 pub fn from_str_radix<T: FromStrRadix>(str: &str, radix: uint) -> Option<T> {
125 FromStrRadix::from_str_radix(str, radix)
128 /// Helper function for testing numeric operations
130 pub fn test_num<T:Num + NumCast + Show>(ten: T, two: T) {
131 assert_eq!(ten.add(&two), cast(12).unwrap());
132 assert_eq!(ten.sub(&two), cast(8).unwrap());
133 assert_eq!(ten.mul(&two), cast(20).unwrap());
134 assert_eq!(ten.div(&two), cast(5).unwrap());
135 assert_eq!(ten.rem(&two), cast(0).unwrap());
137 assert_eq!(ten.add(&two), ten + two);
138 assert_eq!(ten.sub(&two), ten - two);
139 assert_eq!(ten.mul(&two), ten * two);
140 assert_eq!(ten.div(&two), ten / two);
141 assert_eq!(ten.rem(&two), ten % two);
159 macro_rules! test_cast_20(
163 assert_eq!(20u, _20.to_uint().unwrap());
164 assert_eq!(20u8, _20.to_u8().unwrap());
165 assert_eq!(20u16, _20.to_u16().unwrap());
166 assert_eq!(20u32, _20.to_u32().unwrap());
167 assert_eq!(20u64, _20.to_u64().unwrap());
168 assert_eq!(20i, _20.to_int().unwrap());
169 assert_eq!(20i8, _20.to_i8().unwrap());
170 assert_eq!(20i16, _20.to_i16().unwrap());
171 assert_eq!(20i32, _20.to_i32().unwrap());
172 assert_eq!(20i64, _20.to_i64().unwrap());
173 assert_eq!(20f32, _20.to_f32().unwrap());
174 assert_eq!(20f64, _20.to_f64().unwrap());
176 assert_eq!(_20, NumCast::from(20u).unwrap());
177 assert_eq!(_20, NumCast::from(20u8).unwrap());
178 assert_eq!(_20, NumCast::from(20u16).unwrap());
179 assert_eq!(_20, NumCast::from(20u32).unwrap());
180 assert_eq!(_20, NumCast::from(20u64).unwrap());
181 assert_eq!(_20, NumCast::from(20i).unwrap());
182 assert_eq!(_20, NumCast::from(20i8).unwrap());
183 assert_eq!(_20, NumCast::from(20i16).unwrap());
184 assert_eq!(_20, NumCast::from(20i32).unwrap());
185 assert_eq!(_20, NumCast::from(20i64).unwrap());
186 assert_eq!(_20, NumCast::from(20f32).unwrap());
187 assert_eq!(_20, NumCast::from(20f64).unwrap());
189 assert_eq!(_20, cast(20u).unwrap());
190 assert_eq!(_20, cast(20u8).unwrap());
191 assert_eq!(_20, cast(20u16).unwrap());
192 assert_eq!(_20, cast(20u32).unwrap());
193 assert_eq!(_20, cast(20u64).unwrap());
194 assert_eq!(_20, cast(20i).unwrap());
195 assert_eq!(_20, cast(20i8).unwrap());
196 assert_eq!(_20, cast(20i16).unwrap());
197 assert_eq!(_20, cast(20i32).unwrap());
198 assert_eq!(_20, cast(20i64).unwrap());
199 assert_eq!(_20, cast(20f32).unwrap());
200 assert_eq!(_20, cast(20f64).unwrap());
204 #[test] fn test_u8_cast() { test_cast_20!(20u8) }
205 #[test] fn test_u16_cast() { test_cast_20!(20u16) }
206 #[test] fn test_u32_cast() { test_cast_20!(20u32) }
207 #[test] fn test_u64_cast() { test_cast_20!(20u64) }
208 #[test] fn test_uint_cast() { test_cast_20!(20u) }
209 #[test] fn test_i8_cast() { test_cast_20!(20i8) }
210 #[test] fn test_i16_cast() { test_cast_20!(20i16) }
211 #[test] fn test_i32_cast() { test_cast_20!(20i32) }
212 #[test] fn test_i64_cast() { test_cast_20!(20i64) }
213 #[test] fn test_int_cast() { test_cast_20!(20i) }
214 #[test] fn test_f32_cast() { test_cast_20!(20f32) }
215 #[test] fn test_f64_cast() { test_cast_20!(20f64) }
218 fn test_cast_range_int_min() {
219 assert_eq!(int::MIN.to_int(), Some(int::MIN as int));
220 assert_eq!(int::MIN.to_i8(), None);
221 assert_eq!(int::MIN.to_i16(), None);
222 // int::MIN.to_i32() is word-size specific
223 assert_eq!(int::MIN.to_i64(), Some(int::MIN as i64));
224 assert_eq!(int::MIN.to_uint(), None);
225 assert_eq!(int::MIN.to_u8(), None);
226 assert_eq!(int::MIN.to_u16(), None);
227 assert_eq!(int::MIN.to_u32(), None);
228 assert_eq!(int::MIN.to_u64(), None);
230 #[cfg(target_word_size = "32")]
231 fn check_word_size() {
232 assert_eq!(int::MIN.to_i32(), Some(int::MIN as i32));
235 #[cfg(target_word_size = "64")]
236 fn check_word_size() {
237 assert_eq!(int::MIN.to_i32(), None);
244 fn test_cast_range_i8_min() {
245 assert_eq!(i8::MIN.to_int(), Some(i8::MIN as int));
246 assert_eq!(i8::MIN.to_i8(), Some(i8::MIN as i8));
247 assert_eq!(i8::MIN.to_i16(), Some(i8::MIN as i16));
248 assert_eq!(i8::MIN.to_i32(), Some(i8::MIN as i32));
249 assert_eq!(i8::MIN.to_i64(), Some(i8::MIN as i64));
250 assert_eq!(i8::MIN.to_uint(), None);
251 assert_eq!(i8::MIN.to_u8(), None);
252 assert_eq!(i8::MIN.to_u16(), None);
253 assert_eq!(i8::MIN.to_u32(), None);
254 assert_eq!(i8::MIN.to_u64(), None);
258 fn test_cast_range_i16_min() {
259 assert_eq!(i16::MIN.to_int(), Some(i16::MIN as int));
260 assert_eq!(i16::MIN.to_i8(), None);
261 assert_eq!(i16::MIN.to_i16(), Some(i16::MIN as i16));
262 assert_eq!(i16::MIN.to_i32(), Some(i16::MIN as i32));
263 assert_eq!(i16::MIN.to_i64(), Some(i16::MIN as i64));
264 assert_eq!(i16::MIN.to_uint(), None);
265 assert_eq!(i16::MIN.to_u8(), None);
266 assert_eq!(i16::MIN.to_u16(), None);
267 assert_eq!(i16::MIN.to_u32(), None);
268 assert_eq!(i16::MIN.to_u64(), None);
272 fn test_cast_range_i32_min() {
273 assert_eq!(i32::MIN.to_int(), Some(i32::MIN as int));
274 assert_eq!(i32::MIN.to_i8(), None);
275 assert_eq!(i32::MIN.to_i16(), None);
276 assert_eq!(i32::MIN.to_i32(), Some(i32::MIN as i32));
277 assert_eq!(i32::MIN.to_i64(), Some(i32::MIN as i64));
278 assert_eq!(i32::MIN.to_uint(), None);
279 assert_eq!(i32::MIN.to_u8(), None);
280 assert_eq!(i32::MIN.to_u16(), None);
281 assert_eq!(i32::MIN.to_u32(), None);
282 assert_eq!(i32::MIN.to_u64(), None);
286 fn test_cast_range_i64_min() {
287 // i64::MIN.to_int() is word-size specific
288 assert_eq!(i64::MIN.to_i8(), None);
289 assert_eq!(i64::MIN.to_i16(), None);
290 assert_eq!(i64::MIN.to_i32(), None);
291 assert_eq!(i64::MIN.to_i64(), Some(i64::MIN as i64));
292 assert_eq!(i64::MIN.to_uint(), None);
293 assert_eq!(i64::MIN.to_u8(), None);
294 assert_eq!(i64::MIN.to_u16(), None);
295 assert_eq!(i64::MIN.to_u32(), None);
296 assert_eq!(i64::MIN.to_u64(), None);
298 #[cfg(target_word_size = "32")]
299 fn check_word_size() {
300 assert_eq!(i64::MIN.to_int(), None);
303 #[cfg(target_word_size = "64")]
304 fn check_word_size() {
305 assert_eq!(i64::MIN.to_int(), Some(i64::MIN as int));
312 fn test_cast_range_int_max() {
313 assert_eq!(int::MAX.to_int(), Some(int::MAX as int));
314 assert_eq!(int::MAX.to_i8(), None);
315 assert_eq!(int::MAX.to_i16(), None);
316 // int::MAX.to_i32() is word-size specific
317 assert_eq!(int::MAX.to_i64(), Some(int::MAX as i64));
318 assert_eq!(int::MAX.to_u8(), None);
319 assert_eq!(int::MAX.to_u16(), None);
320 // int::MAX.to_u32() is word-size specific
321 assert_eq!(int::MAX.to_u64(), Some(int::MAX as u64));
323 #[cfg(target_word_size = "32")]
324 fn check_word_size() {
325 assert_eq!(int::MAX.to_i32(), Some(int::MAX as i32));
326 assert_eq!(int::MAX.to_u32(), Some(int::MAX as u32));
329 #[cfg(target_word_size = "64")]
330 fn check_word_size() {
331 assert_eq!(int::MAX.to_i32(), None);
332 assert_eq!(int::MAX.to_u32(), None);
339 fn test_cast_range_i8_max() {
340 assert_eq!(i8::MAX.to_int(), Some(i8::MAX as int));
341 assert_eq!(i8::MAX.to_i8(), Some(i8::MAX as i8));
342 assert_eq!(i8::MAX.to_i16(), Some(i8::MAX as i16));
343 assert_eq!(i8::MAX.to_i32(), Some(i8::MAX as i32));
344 assert_eq!(i8::MAX.to_i64(), Some(i8::MAX as i64));
345 assert_eq!(i8::MAX.to_uint(), Some(i8::MAX as uint));
346 assert_eq!(i8::MAX.to_u8(), Some(i8::MAX as u8));
347 assert_eq!(i8::MAX.to_u16(), Some(i8::MAX as u16));
348 assert_eq!(i8::MAX.to_u32(), Some(i8::MAX as u32));
349 assert_eq!(i8::MAX.to_u64(), Some(i8::MAX as u64));
353 fn test_cast_range_i16_max() {
354 assert_eq!(i16::MAX.to_int(), Some(i16::MAX as int));
355 assert_eq!(i16::MAX.to_i8(), None);
356 assert_eq!(i16::MAX.to_i16(), Some(i16::MAX as i16));
357 assert_eq!(i16::MAX.to_i32(), Some(i16::MAX as i32));
358 assert_eq!(i16::MAX.to_i64(), Some(i16::MAX as i64));
359 assert_eq!(i16::MAX.to_uint(), Some(i16::MAX as uint));
360 assert_eq!(i16::MAX.to_u8(), None);
361 assert_eq!(i16::MAX.to_u16(), Some(i16::MAX as u16));
362 assert_eq!(i16::MAX.to_u32(), Some(i16::MAX as u32));
363 assert_eq!(i16::MAX.to_u64(), Some(i16::MAX as u64));
367 fn test_cast_range_i32_max() {
368 assert_eq!(i32::MAX.to_int(), Some(i32::MAX as int));
369 assert_eq!(i32::MAX.to_i8(), None);
370 assert_eq!(i32::MAX.to_i16(), None);
371 assert_eq!(i32::MAX.to_i32(), Some(i32::MAX as i32));
372 assert_eq!(i32::MAX.to_i64(), Some(i32::MAX as i64));
373 assert_eq!(i32::MAX.to_uint(), Some(i32::MAX as uint));
374 assert_eq!(i32::MAX.to_u8(), None);
375 assert_eq!(i32::MAX.to_u16(), None);
376 assert_eq!(i32::MAX.to_u32(), Some(i32::MAX as u32));
377 assert_eq!(i32::MAX.to_u64(), Some(i32::MAX as u64));
381 fn test_cast_range_i64_max() {
382 // i64::MAX.to_int() is word-size specific
383 assert_eq!(i64::MAX.to_i8(), None);
384 assert_eq!(i64::MAX.to_i16(), None);
385 assert_eq!(i64::MAX.to_i32(), None);
386 assert_eq!(i64::MAX.to_i64(), Some(i64::MAX as i64));
387 // i64::MAX.to_uint() is word-size specific
388 assert_eq!(i64::MAX.to_u8(), None);
389 assert_eq!(i64::MAX.to_u16(), None);
390 assert_eq!(i64::MAX.to_u32(), None);
391 assert_eq!(i64::MAX.to_u64(), Some(i64::MAX as u64));
393 #[cfg(target_word_size = "32")]
394 fn check_word_size() {
395 assert_eq!(i64::MAX.to_int(), None);
396 assert_eq!(i64::MAX.to_uint(), None);
399 #[cfg(target_word_size = "64")]
400 fn check_word_size() {
401 assert_eq!(i64::MAX.to_int(), Some(i64::MAX as int));
402 assert_eq!(i64::MAX.to_uint(), Some(i64::MAX as uint));
409 fn test_cast_range_uint_min() {
410 assert_eq!(uint::MIN.to_int(), Some(uint::MIN as int));
411 assert_eq!(uint::MIN.to_i8(), Some(uint::MIN as i8));
412 assert_eq!(uint::MIN.to_i16(), Some(uint::MIN as i16));
413 assert_eq!(uint::MIN.to_i32(), Some(uint::MIN as i32));
414 assert_eq!(uint::MIN.to_i64(), Some(uint::MIN as i64));
415 assert_eq!(uint::MIN.to_uint(), Some(uint::MIN as uint));
416 assert_eq!(uint::MIN.to_u8(), Some(uint::MIN as u8));
417 assert_eq!(uint::MIN.to_u16(), Some(uint::MIN as u16));
418 assert_eq!(uint::MIN.to_u32(), Some(uint::MIN as u32));
419 assert_eq!(uint::MIN.to_u64(), Some(uint::MIN as u64));
423 fn test_cast_range_u8_min() {
424 assert_eq!(u8::MIN.to_int(), Some(u8::MIN as int));
425 assert_eq!(u8::MIN.to_i8(), Some(u8::MIN as i8));
426 assert_eq!(u8::MIN.to_i16(), Some(u8::MIN as i16));
427 assert_eq!(u8::MIN.to_i32(), Some(u8::MIN as i32));
428 assert_eq!(u8::MIN.to_i64(), Some(u8::MIN as i64));
429 assert_eq!(u8::MIN.to_uint(), Some(u8::MIN as uint));
430 assert_eq!(u8::MIN.to_u8(), Some(u8::MIN as u8));
431 assert_eq!(u8::MIN.to_u16(), Some(u8::MIN as u16));
432 assert_eq!(u8::MIN.to_u32(), Some(u8::MIN as u32));
433 assert_eq!(u8::MIN.to_u64(), Some(u8::MIN as u64));
437 fn test_cast_range_u16_min() {
438 assert_eq!(u16::MIN.to_int(), Some(u16::MIN as int));
439 assert_eq!(u16::MIN.to_i8(), Some(u16::MIN as i8));
440 assert_eq!(u16::MIN.to_i16(), Some(u16::MIN as i16));
441 assert_eq!(u16::MIN.to_i32(), Some(u16::MIN as i32));
442 assert_eq!(u16::MIN.to_i64(), Some(u16::MIN as i64));
443 assert_eq!(u16::MIN.to_uint(), Some(u16::MIN as uint));
444 assert_eq!(u16::MIN.to_u8(), Some(u16::MIN as u8));
445 assert_eq!(u16::MIN.to_u16(), Some(u16::MIN as u16));
446 assert_eq!(u16::MIN.to_u32(), Some(u16::MIN as u32));
447 assert_eq!(u16::MIN.to_u64(), Some(u16::MIN as u64));
451 fn test_cast_range_u32_min() {
452 assert_eq!(u32::MIN.to_int(), Some(u32::MIN as int));
453 assert_eq!(u32::MIN.to_i8(), Some(u32::MIN as i8));
454 assert_eq!(u32::MIN.to_i16(), Some(u32::MIN as i16));
455 assert_eq!(u32::MIN.to_i32(), Some(u32::MIN as i32));
456 assert_eq!(u32::MIN.to_i64(), Some(u32::MIN as i64));
457 assert_eq!(u32::MIN.to_uint(), Some(u32::MIN as uint));
458 assert_eq!(u32::MIN.to_u8(), Some(u32::MIN as u8));
459 assert_eq!(u32::MIN.to_u16(), Some(u32::MIN as u16));
460 assert_eq!(u32::MIN.to_u32(), Some(u32::MIN as u32));
461 assert_eq!(u32::MIN.to_u64(), Some(u32::MIN as u64));
465 fn test_cast_range_u64_min() {
466 assert_eq!(u64::MIN.to_int(), Some(u64::MIN as int));
467 assert_eq!(u64::MIN.to_i8(), Some(u64::MIN as i8));
468 assert_eq!(u64::MIN.to_i16(), Some(u64::MIN as i16));
469 assert_eq!(u64::MIN.to_i32(), Some(u64::MIN as i32));
470 assert_eq!(u64::MIN.to_i64(), Some(u64::MIN as i64));
471 assert_eq!(u64::MIN.to_uint(), Some(u64::MIN as uint));
472 assert_eq!(u64::MIN.to_u8(), Some(u64::MIN as u8));
473 assert_eq!(u64::MIN.to_u16(), Some(u64::MIN as u16));
474 assert_eq!(u64::MIN.to_u32(), Some(u64::MIN as u32));
475 assert_eq!(u64::MIN.to_u64(), Some(u64::MIN as u64));
479 fn test_cast_range_uint_max() {
480 assert_eq!(uint::MAX.to_int(), None);
481 assert_eq!(uint::MAX.to_i8(), None);
482 assert_eq!(uint::MAX.to_i16(), None);
483 assert_eq!(uint::MAX.to_i32(), None);
484 // uint::MAX.to_i64() is word-size specific
485 assert_eq!(uint::MAX.to_u8(), None);
486 assert_eq!(uint::MAX.to_u16(), None);
487 // uint::MAX.to_u32() is word-size specific
488 assert_eq!(uint::MAX.to_u64(), Some(uint::MAX as u64));
490 #[cfg(target_word_size = "32")]
491 fn check_word_size() {
492 assert_eq!(uint::MAX.to_u32(), Some(uint::MAX as u32));
493 assert_eq!(uint::MAX.to_i64(), Some(uint::MAX as i64));
496 #[cfg(target_word_size = "64")]
497 fn check_word_size() {
498 assert_eq!(uint::MAX.to_u32(), None);
499 assert_eq!(uint::MAX.to_i64(), None);
506 fn test_cast_range_u8_max() {
507 assert_eq!(u8::MAX.to_int(), Some(u8::MAX as int));
508 assert_eq!(u8::MAX.to_i8(), None);
509 assert_eq!(u8::MAX.to_i16(), Some(u8::MAX as i16));
510 assert_eq!(u8::MAX.to_i32(), Some(u8::MAX as i32));
511 assert_eq!(u8::MAX.to_i64(), Some(u8::MAX as i64));
512 assert_eq!(u8::MAX.to_uint(), Some(u8::MAX as uint));
513 assert_eq!(u8::MAX.to_u8(), Some(u8::MAX as u8));
514 assert_eq!(u8::MAX.to_u16(), Some(u8::MAX as u16));
515 assert_eq!(u8::MAX.to_u32(), Some(u8::MAX as u32));
516 assert_eq!(u8::MAX.to_u64(), Some(u8::MAX as u64));
520 fn test_cast_range_u16_max() {
521 assert_eq!(u16::MAX.to_int(), Some(u16::MAX as int));
522 assert_eq!(u16::MAX.to_i8(), None);
523 assert_eq!(u16::MAX.to_i16(), None);
524 assert_eq!(u16::MAX.to_i32(), Some(u16::MAX as i32));
525 assert_eq!(u16::MAX.to_i64(), Some(u16::MAX as i64));
526 assert_eq!(u16::MAX.to_uint(), Some(u16::MAX as uint));
527 assert_eq!(u16::MAX.to_u8(), None);
528 assert_eq!(u16::MAX.to_u16(), Some(u16::MAX as u16));
529 assert_eq!(u16::MAX.to_u32(), Some(u16::MAX as u32));
530 assert_eq!(u16::MAX.to_u64(), Some(u16::MAX as u64));
534 fn test_cast_range_u32_max() {
535 // u32::MAX.to_int() is word-size specific
536 assert_eq!(u32::MAX.to_i8(), None);
537 assert_eq!(u32::MAX.to_i16(), None);
538 assert_eq!(u32::MAX.to_i32(), None);
539 assert_eq!(u32::MAX.to_i64(), Some(u32::MAX as i64));
540 assert_eq!(u32::MAX.to_uint(), Some(u32::MAX as uint));
541 assert_eq!(u32::MAX.to_u8(), None);
542 assert_eq!(u32::MAX.to_u16(), None);
543 assert_eq!(u32::MAX.to_u32(), Some(u32::MAX as u32));
544 assert_eq!(u32::MAX.to_u64(), Some(u32::MAX as u64));
546 #[cfg(target_word_size = "32")]
547 fn check_word_size() {
548 assert_eq!(u32::MAX.to_int(), None);
551 #[cfg(target_word_size = "64")]
552 fn check_word_size() {
553 assert_eq!(u32::MAX.to_int(), Some(u32::MAX as int));
560 fn test_cast_range_u64_max() {
561 assert_eq!(u64::MAX.to_int(), None);
562 assert_eq!(u64::MAX.to_i8(), None);
563 assert_eq!(u64::MAX.to_i16(), None);
564 assert_eq!(u64::MAX.to_i32(), None);
565 assert_eq!(u64::MAX.to_i64(), None);
566 // u64::MAX.to_uint() is word-size specific
567 assert_eq!(u64::MAX.to_u8(), None);
568 assert_eq!(u64::MAX.to_u16(), None);
569 assert_eq!(u64::MAX.to_u32(), None);
570 assert_eq!(u64::MAX.to_u64(), Some(u64::MAX as u64));
572 #[cfg(target_word_size = "32")]
573 fn check_word_size() {
574 assert_eq!(u64::MAX.to_uint(), None);
577 #[cfg(target_word_size = "64")]
578 fn check_word_size() {
579 assert_eq!(u64::MAX.to_uint(), Some(u64::MAX as uint));
586 fn test_saturating_add_uint() {
588 assert_eq!(3u.saturating_add(5u), 8u);
589 assert_eq!(3u.saturating_add(MAX-1), MAX);
590 assert_eq!(MAX.saturating_add(MAX), MAX);
591 assert_eq!((MAX-2).saturating_add(1), MAX-1);
595 fn test_saturating_sub_uint() {
597 assert_eq!(5u.saturating_sub(3u), 2u);
598 assert_eq!(3u.saturating_sub(5u), 0u);
599 assert_eq!(0u.saturating_sub(1u), 0u);
600 assert_eq!((MAX-1).saturating_sub(MAX), 0);
604 fn test_saturating_add_int() {
606 assert_eq!(3i.saturating_add(5i), 8i);
607 assert_eq!(3i.saturating_add(MAX-1), MAX);
608 assert_eq!(MAX.saturating_add(MAX), MAX);
609 assert_eq!((MAX-2).saturating_add(1), MAX-1);
610 assert_eq!(3i.saturating_add(-5i), -2i);
611 assert_eq!(MIN.saturating_add(-1i), MIN);
612 assert_eq!((-2i).saturating_add(-MAX), MIN);
616 fn test_saturating_sub_int() {
618 assert_eq!(3i.saturating_sub(5i), -2i);
619 assert_eq!(MIN.saturating_sub(1i), MIN);
620 assert_eq!((-2i).saturating_sub(MAX), MIN);
621 assert_eq!(3i.saturating_sub(-5i), 8i);
622 assert_eq!(3i.saturating_sub(-(MAX-1)), MAX);
623 assert_eq!(MAX.saturating_sub(-MAX), MAX);
624 assert_eq!((MAX-2).saturating_sub(-1), MAX-1);
628 fn test_checked_add() {
629 let five_less = uint::MAX - 5;
630 assert_eq!(five_less.checked_add(&0), Some(uint::MAX - 5));
631 assert_eq!(five_less.checked_add(&1), Some(uint::MAX - 4));
632 assert_eq!(five_less.checked_add(&2), Some(uint::MAX - 3));
633 assert_eq!(five_less.checked_add(&3), Some(uint::MAX - 2));
634 assert_eq!(five_less.checked_add(&4), Some(uint::MAX - 1));
635 assert_eq!(five_less.checked_add(&5), Some(uint::MAX));
636 assert_eq!(five_less.checked_add(&6), None);
637 assert_eq!(five_less.checked_add(&7), None);
641 fn test_checked_sub() {
642 assert_eq!(5u.checked_sub(&0), Some(5));
643 assert_eq!(5u.checked_sub(&1), Some(4));
644 assert_eq!(5u.checked_sub(&2), Some(3));
645 assert_eq!(5u.checked_sub(&3), Some(2));
646 assert_eq!(5u.checked_sub(&4), Some(1));
647 assert_eq!(5u.checked_sub(&5), Some(0));
648 assert_eq!(5u.checked_sub(&6), None);
649 assert_eq!(5u.checked_sub(&7), None);
653 fn test_checked_mul() {
654 let third = uint::MAX / 3;
655 assert_eq!(third.checked_mul(&0), Some(0));
656 assert_eq!(third.checked_mul(&1), Some(third));
657 assert_eq!(third.checked_mul(&2), Some(third * 2));
658 assert_eq!(third.checked_mul(&3), Some(third * 3));
659 assert_eq!(third.checked_mul(&4), None);
662 macro_rules! test_next_power_of_two(
663 ($test_name:ident, $T:ident) => (
666 assert_eq!(next_power_of_two::<$T>(0), 0);
667 let mut next_power = 1;
668 for i in range::<$T>(1, 40) {
669 assert_eq!(next_power_of_two(i), next_power);
670 if i == next_power { next_power *= 2 }
676 test_next_power_of_two!(test_next_power_of_two_u8, u8)
677 test_next_power_of_two!(test_next_power_of_two_u16, u16)
678 test_next_power_of_two!(test_next_power_of_two_u32, u32)
679 test_next_power_of_two!(test_next_power_of_two_u64, u64)
680 test_next_power_of_two!(test_next_power_of_two_uint, uint)
682 macro_rules! test_checked_next_power_of_two(
683 ($test_name:ident, $T:ident) => (
686 assert_eq!(checked_next_power_of_two::<$T>(0), None);
687 let mut next_power = 1;
688 for i in range::<$T>(1, 40) {
689 assert_eq!(checked_next_power_of_two(i), Some(next_power));
690 if i == next_power { next_power *= 2 }
692 assert!(checked_next_power_of_two::<$T>($T::MAX / 2).is_some());
693 assert_eq!(checked_next_power_of_two::<$T>($T::MAX - 1), None);
694 assert_eq!(checked_next_power_of_two::<$T>($T::MAX), None);
699 test_checked_next_power_of_two!(test_checked_next_power_of_two_u8, u8)
700 test_checked_next_power_of_two!(test_checked_next_power_of_two_u16, u16)
701 test_checked_next_power_of_two!(test_checked_next_power_of_two_u32, u32)
702 test_checked_next_power_of_two!(test_checked_next_power_of_two_u64, u64)
703 test_checked_next_power_of_two!(test_checked_next_power_of_two_uint, uint)
705 #[deriving(PartialEq, Show)]
706 struct Value { x: int }
708 impl ToPrimitive for Value {
709 fn to_i64(&self) -> Option<i64> { self.x.to_i64() }
710 fn to_u64(&self) -> Option<u64> { self.x.to_u64() }
713 impl FromPrimitive for Value {
714 fn from_i64(n: i64) -> Option<Value> { Some(Value { x: n as int }) }
715 fn from_u64(n: u64) -> Option<Value> { Some(Value { x: n as int }) }
719 fn test_to_primitive() {
720 let value = Value { x: 5 };
721 assert_eq!(value.to_int(), Some(5));
722 assert_eq!(value.to_i8(), Some(5));
723 assert_eq!(value.to_i16(), Some(5));
724 assert_eq!(value.to_i32(), Some(5));
725 assert_eq!(value.to_i64(), Some(5));
726 assert_eq!(value.to_uint(), Some(5));
727 assert_eq!(value.to_u8(), Some(5));
728 assert_eq!(value.to_u16(), Some(5));
729 assert_eq!(value.to_u32(), Some(5));
730 assert_eq!(value.to_u64(), Some(5));
731 assert_eq!(value.to_f32(), Some(5f32));
732 assert_eq!(value.to_f64(), Some(5f64));
736 fn test_from_primitive() {
737 assert_eq!(from_int(5), Some(Value { x: 5 }));
738 assert_eq!(from_i8(5), Some(Value { x: 5 }));
739 assert_eq!(from_i16(5), Some(Value { x: 5 }));
740 assert_eq!(from_i32(5), Some(Value { x: 5 }));
741 assert_eq!(from_i64(5), Some(Value { x: 5 }));
742 assert_eq!(from_uint(5), Some(Value { x: 5 }));
743 assert_eq!(from_u8(5), Some(Value { x: 5 }));
744 assert_eq!(from_u16(5), Some(Value { x: 5 }));
745 assert_eq!(from_u32(5), Some(Value { x: 5 }));
746 assert_eq!(from_u64(5), Some(Value { x: 5 }));
747 assert_eq!(from_f32(5f32), Some(Value { x: 5 }));
748 assert_eq!(from_f64(5f64), Some(Value { x: 5 }));
753 fn naive_pow<T: One + Mul<T, T>>(base: T, exp: uint) -> T {
754 range(0, exp).fold(one::<T>(), |acc, _| acc * base)
756 macro_rules! assert_pow(
757 (($num:expr, $exp:expr) => $expected:expr) => {{
758 let result = pow($num, $exp);
759 assert_eq!(result, $expected);
760 assert_eq!(result, naive_pow($num, $exp));
763 assert_pow!((3, 0 ) => 1);
764 assert_pow!((5, 1 ) => 5);
765 assert_pow!((-4, 2 ) => 16);
766 assert_pow!((0.5, 5 ) => 0.03125);
767 assert_pow!((8, 3 ) => 512);
768 assert_pow!((8.0, 5 ) => 32768.0);
769 assert_pow!((8.5, 5 ) => 44370.53125);
770 assert_pow!((2u64, 50) => 1125899906842624);
778 use self::test::Bencher;
783 fn bench_pow_function(b: &mut Bencher) {
784 let v = Vec::from_fn(1024, |n| n);
785 b.iter(|| {v.iter().fold(0, |old, new| num::pow(old, *new));});