1 | use std::borrow::{Borrow, BorrowMut}; |
2 | use std::cmp; |
3 | use std::convert::TryFrom; |
4 | use std::fmt; |
5 | use std::hash::{Hash, Hasher}; |
6 | use std::mem::MaybeUninit; |
7 | use std::ops::{Deref, DerefMut}; |
8 | #[cfg (feature="std" )] |
9 | use std::path::Path; |
10 | use std::ptr; |
11 | use std::slice; |
12 | use std::str; |
13 | use std::str::FromStr; |
14 | use std::str::Utf8Error; |
15 | |
16 | use crate::CapacityError; |
17 | use crate::LenUint; |
18 | use crate::char::encode_utf8; |
19 | use crate::utils::MakeMaybeUninit; |
20 | |
21 | #[cfg (feature="serde" )] |
22 | use serde::{Serialize, Deserialize, Serializer, Deserializer}; |
23 | |
24 | |
25 | /// A string with a fixed capacity. |
26 | /// |
27 | /// The `ArrayString` is a string backed by a fixed size array. It keeps track |
28 | /// of its length, and is parameterized by `CAP` for the maximum capacity. |
29 | /// |
30 | /// `CAP` is of type `usize` but is range limited to `u32::MAX`; attempting to create larger |
31 | /// arrayvecs with larger capacity will panic. |
32 | /// |
33 | /// The string is a contiguous value that you can store directly on the stack |
34 | /// if needed. |
35 | #[derive (Copy)] |
36 | #[repr (C)] |
37 | pub struct ArrayString<const CAP: usize> { |
38 | // the `len` first elements of the array are initialized |
39 | len: LenUint, |
40 | xs: [MaybeUninit<u8>; CAP], |
41 | } |
42 | |
43 | impl<const CAP: usize> Default for ArrayString<CAP> |
44 | { |
45 | /// Return an empty `ArrayString` |
46 | fn default() -> ArrayString<CAP> { |
47 | ArrayString::new() |
48 | } |
49 | } |
50 | |
51 | impl<const CAP: usize> ArrayString<CAP> |
52 | { |
53 | /// Create a new empty `ArrayString`. |
54 | /// |
55 | /// Capacity is inferred from the type parameter. |
56 | /// |
57 | /// ``` |
58 | /// use arrayvec::ArrayString; |
59 | /// |
60 | /// let mut string = ArrayString::<16>::new(); |
61 | /// string.push_str("foo" ); |
62 | /// assert_eq!(&string[..], "foo" ); |
63 | /// assert_eq!(string.capacity(), 16); |
64 | /// ``` |
65 | pub fn new() -> ArrayString<CAP> { |
66 | assert_capacity_limit!(CAP); |
67 | unsafe { |
68 | ArrayString { xs: MaybeUninit::uninit().assume_init(), len: 0 } |
69 | } |
70 | } |
71 | |
72 | /// Create a new empty `ArrayString` (const fn). |
73 | /// |
74 | /// Capacity is inferred from the type parameter. |
75 | /// |
76 | /// ``` |
77 | /// use arrayvec::ArrayString; |
78 | /// |
79 | /// static ARRAY: ArrayString<1024> = ArrayString::new_const(); |
80 | /// ``` |
81 | pub const fn new_const() -> ArrayString<CAP> { |
82 | assert_capacity_limit_const!(CAP); |
83 | ArrayString { xs: MakeMaybeUninit::ARRAY, len: 0 } |
84 | } |
85 | |
86 | /// Return the length of the string. |
87 | #[inline ] |
88 | pub const fn len(&self) -> usize { self.len as usize } |
89 | |
90 | /// Returns whether the string is empty. |
91 | #[inline ] |
92 | pub const fn is_empty(&self) -> bool { self.len() == 0 } |
93 | |
94 | /// Create a new `ArrayString` from a `str`. |
95 | /// |
96 | /// Capacity is inferred from the type parameter. |
97 | /// |
98 | /// **Errors** if the backing array is not large enough to fit the string. |
99 | /// |
100 | /// ``` |
101 | /// use arrayvec::ArrayString; |
102 | /// |
103 | /// let mut string = ArrayString::<3>::from("foo" ).unwrap(); |
104 | /// assert_eq!(&string[..], "foo" ); |
105 | /// assert_eq!(string.len(), 3); |
106 | /// assert_eq!(string.capacity(), 3); |
107 | /// ``` |
108 | pub fn from(s: &str) -> Result<Self, CapacityError<&str>> { |
109 | let mut arraystr = Self::new(); |
110 | arraystr.try_push_str(s)?; |
111 | Ok(arraystr) |
112 | } |
113 | |
114 | /// Create a new `ArrayString` from a byte string literal. |
115 | /// |
116 | /// **Errors** if the byte string literal is not valid UTF-8. |
117 | /// |
118 | /// ``` |
119 | /// use arrayvec::ArrayString; |
120 | /// |
121 | /// let string = ArrayString::from_byte_string(b"hello world" ).unwrap(); |
122 | /// ``` |
123 | pub fn from_byte_string(b: &[u8; CAP]) -> Result<Self, Utf8Error> { |
124 | let len = str::from_utf8(b)?.len(); |
125 | debug_assert_eq!(len, CAP); |
126 | let mut vec = Self::new(); |
127 | unsafe { |
128 | (b as *const [u8; CAP] as *const [MaybeUninit<u8>; CAP]) |
129 | .copy_to_nonoverlapping(&mut vec.xs as *mut [MaybeUninit<u8>; CAP], 1); |
130 | vec.set_len(CAP); |
131 | } |
132 | Ok(vec) |
133 | } |
134 | |
135 | /// Create a new `ArrayString` value fully filled with ASCII NULL characters (`\0`). Useful |
136 | /// to be used as a buffer to collect external data or as a buffer for intermediate processing. |
137 | /// |
138 | /// ``` |
139 | /// use arrayvec::ArrayString; |
140 | /// |
141 | /// let string = ArrayString::<16>::zero_filled(); |
142 | /// assert_eq!(string.len(), 16); |
143 | /// ``` |
144 | #[inline ] |
145 | pub fn zero_filled() -> Self { |
146 | assert_capacity_limit!(CAP); |
147 | // SAFETY: `assert_capacity_limit` asserts that `len` won't overflow and |
148 | // `zeroed` fully fills the array with nulls. |
149 | unsafe { |
150 | ArrayString { |
151 | xs: MaybeUninit::zeroed().assume_init(), |
152 | len: CAP as _ |
153 | } |
154 | } |
155 | } |
156 | |
157 | /// Return the capacity of the `ArrayString`. |
158 | /// |
159 | /// ``` |
160 | /// use arrayvec::ArrayString; |
161 | /// |
162 | /// let string = ArrayString::<3>::new(); |
163 | /// assert_eq!(string.capacity(), 3); |
164 | /// ``` |
165 | #[inline (always)] |
166 | pub const fn capacity(&self) -> usize { CAP } |
167 | |
168 | /// Return if the `ArrayString` is completely filled. |
169 | /// |
170 | /// ``` |
171 | /// use arrayvec::ArrayString; |
172 | /// |
173 | /// let mut string = ArrayString::<1>::new(); |
174 | /// assert!(!string.is_full()); |
175 | /// string.push_str("A" ); |
176 | /// assert!(string.is_full()); |
177 | /// ``` |
178 | pub const fn is_full(&self) -> bool { self.len() == self.capacity() } |
179 | |
180 | /// Returns the capacity left in the `ArrayString`. |
181 | /// |
182 | /// ``` |
183 | /// use arrayvec::ArrayString; |
184 | /// |
185 | /// let mut string = ArrayString::<3>::from("abc" ).unwrap(); |
186 | /// string.pop(); |
187 | /// assert_eq!(string.remaining_capacity(), 1); |
188 | /// ``` |
189 | pub const fn remaining_capacity(&self) -> usize { |
190 | self.capacity() - self.len() |
191 | } |
192 | |
193 | /// Adds the given char to the end of the string. |
194 | /// |
195 | /// ***Panics*** if the backing array is not large enough to fit the additional char. |
196 | /// |
197 | /// ``` |
198 | /// use arrayvec::ArrayString; |
199 | /// |
200 | /// let mut string = ArrayString::<2>::new(); |
201 | /// |
202 | /// string.push('a' ); |
203 | /// string.push('b' ); |
204 | /// |
205 | /// assert_eq!(&string[..], "ab" ); |
206 | /// ``` |
207 | #[track_caller ] |
208 | pub fn push(&mut self, c: char) { |
209 | self.try_push(c).unwrap(); |
210 | } |
211 | |
212 | /// Adds the given char to the end of the string. |
213 | /// |
214 | /// Returns `Ok` if the push succeeds. |
215 | /// |
216 | /// **Errors** if the backing array is not large enough to fit the additional char. |
217 | /// |
218 | /// ``` |
219 | /// use arrayvec::ArrayString; |
220 | /// |
221 | /// let mut string = ArrayString::<2>::new(); |
222 | /// |
223 | /// string.try_push('a' ).unwrap(); |
224 | /// string.try_push('b' ).unwrap(); |
225 | /// let overflow = string.try_push('c' ); |
226 | /// |
227 | /// assert_eq!(&string[..], "ab" ); |
228 | /// assert_eq!(overflow.unwrap_err().element(), 'c' ); |
229 | /// ``` |
230 | pub fn try_push(&mut self, c: char) -> Result<(), CapacityError<char>> { |
231 | let len = self.len(); |
232 | unsafe { |
233 | let ptr = self.as_mut_ptr().add(len); |
234 | let remaining_cap = self.capacity() - len; |
235 | match encode_utf8(c, ptr, remaining_cap) { |
236 | Ok(n) => { |
237 | self.set_len(len + n); |
238 | Ok(()) |
239 | } |
240 | Err(_) => Err(CapacityError::new(c)), |
241 | } |
242 | } |
243 | } |
244 | |
245 | /// Adds the given string slice to the end of the string. |
246 | /// |
247 | /// ***Panics*** if the backing array is not large enough to fit the string. |
248 | /// |
249 | /// ``` |
250 | /// use arrayvec::ArrayString; |
251 | /// |
252 | /// let mut string = ArrayString::<2>::new(); |
253 | /// |
254 | /// string.push_str("a" ); |
255 | /// string.push_str("d" ); |
256 | /// |
257 | /// assert_eq!(&string[..], "ad" ); |
258 | /// ``` |
259 | #[track_caller ] |
260 | pub fn push_str(&mut self, s: &str) { |
261 | self.try_push_str(s).unwrap() |
262 | } |
263 | |
264 | /// Adds the given string slice to the end of the string. |
265 | /// |
266 | /// Returns `Ok` if the push succeeds. |
267 | /// |
268 | /// **Errors** if the backing array is not large enough to fit the string. |
269 | /// |
270 | /// ``` |
271 | /// use arrayvec::ArrayString; |
272 | /// |
273 | /// let mut string = ArrayString::<2>::new(); |
274 | /// |
275 | /// string.try_push_str("a" ).unwrap(); |
276 | /// let overflow1 = string.try_push_str("bc" ); |
277 | /// string.try_push_str("d" ).unwrap(); |
278 | /// let overflow2 = string.try_push_str("ef" ); |
279 | /// |
280 | /// assert_eq!(&string[..], "ad" ); |
281 | /// assert_eq!(overflow1.unwrap_err().element(), "bc" ); |
282 | /// assert_eq!(overflow2.unwrap_err().element(), "ef" ); |
283 | /// ``` |
284 | pub fn try_push_str<'a>(&mut self, s: &'a str) -> Result<(), CapacityError<&'a str>> { |
285 | if s.len() > self.capacity() - self.len() { |
286 | return Err(CapacityError::new(s)); |
287 | } |
288 | unsafe { |
289 | let dst = self.as_mut_ptr().add(self.len()); |
290 | let src = s.as_ptr(); |
291 | ptr::copy_nonoverlapping(src, dst, s.len()); |
292 | let newl = self.len() + s.len(); |
293 | self.set_len(newl); |
294 | } |
295 | Ok(()) |
296 | } |
297 | |
298 | /// Removes the last character from the string and returns it. |
299 | /// |
300 | /// Returns `None` if this `ArrayString` is empty. |
301 | /// |
302 | /// ``` |
303 | /// use arrayvec::ArrayString; |
304 | /// |
305 | /// let mut s = ArrayString::<3>::from("foo" ).unwrap(); |
306 | /// |
307 | /// assert_eq!(s.pop(), Some('o' )); |
308 | /// assert_eq!(s.pop(), Some('o' )); |
309 | /// assert_eq!(s.pop(), Some('f' )); |
310 | /// |
311 | /// assert_eq!(s.pop(), None); |
312 | /// ``` |
313 | pub fn pop(&mut self) -> Option<char> { |
314 | let ch = match self.chars().rev().next() { |
315 | Some(ch) => ch, |
316 | None => return None, |
317 | }; |
318 | let new_len = self.len() - ch.len_utf8(); |
319 | unsafe { |
320 | self.set_len(new_len); |
321 | } |
322 | Some(ch) |
323 | } |
324 | |
325 | /// Shortens this `ArrayString` to the specified length. |
326 | /// |
327 | /// If `new_len` is greater than the string’s current length, this has no |
328 | /// effect. |
329 | /// |
330 | /// ***Panics*** if `new_len` does not lie on a `char` boundary. |
331 | /// |
332 | /// ``` |
333 | /// use arrayvec::ArrayString; |
334 | /// |
335 | /// let mut string = ArrayString::<6>::from("foobar" ).unwrap(); |
336 | /// string.truncate(3); |
337 | /// assert_eq!(&string[..], "foo" ); |
338 | /// string.truncate(4); |
339 | /// assert_eq!(&string[..], "foo" ); |
340 | /// ``` |
341 | pub fn truncate(&mut self, new_len: usize) { |
342 | if new_len <= self.len() { |
343 | assert!(self.is_char_boundary(new_len)); |
344 | unsafe { |
345 | // In libstd truncate is called on the underlying vector, |
346 | // which in turns drops each element. |
347 | // As we know we don't have to worry about Drop, |
348 | // we can just set the length (a la clear.) |
349 | self.set_len(new_len); |
350 | } |
351 | } |
352 | } |
353 | |
354 | /// Removes a `char` from this `ArrayString` at a byte position and returns it. |
355 | /// |
356 | /// This is an `O(n)` operation, as it requires copying every element in the |
357 | /// array. |
358 | /// |
359 | /// ***Panics*** if `idx` is larger than or equal to the `ArrayString`’s length, |
360 | /// or if it does not lie on a `char` boundary. |
361 | /// |
362 | /// ``` |
363 | /// use arrayvec::ArrayString; |
364 | /// |
365 | /// let mut s = ArrayString::<3>::from("foo" ).unwrap(); |
366 | /// |
367 | /// assert_eq!(s.remove(0), 'f' ); |
368 | /// assert_eq!(s.remove(1), 'o' ); |
369 | /// assert_eq!(s.remove(0), 'o' ); |
370 | /// ``` |
371 | pub fn remove(&mut self, idx: usize) -> char { |
372 | let ch = match self[idx..].chars().next() { |
373 | Some(ch) => ch, |
374 | None => panic!("cannot remove a char from the end of a string" ), |
375 | }; |
376 | |
377 | let next = idx + ch.len_utf8(); |
378 | let len = self.len(); |
379 | let ptr = self.as_mut_ptr(); |
380 | unsafe { |
381 | ptr::copy( |
382 | ptr.add(next), |
383 | ptr.add(idx), |
384 | len - next); |
385 | self.set_len(len - (next - idx)); |
386 | } |
387 | ch |
388 | } |
389 | |
390 | /// Make the string empty. |
391 | pub fn clear(&mut self) { |
392 | unsafe { |
393 | self.set_len(0); |
394 | } |
395 | } |
396 | |
397 | /// Set the strings’s length. |
398 | /// |
399 | /// This function is `unsafe` because it changes the notion of the |
400 | /// number of “valid” bytes in the string. Use with care. |
401 | /// |
402 | /// This method uses *debug assertions* to check the validity of `length` |
403 | /// and may use other debug assertions. |
404 | pub unsafe fn set_len(&mut self, length: usize) { |
405 | // type invariant that capacity always fits in LenUint |
406 | debug_assert!(length <= self.capacity()); |
407 | self.len = length as LenUint; |
408 | } |
409 | |
410 | /// Return a string slice of the whole `ArrayString`. |
411 | pub fn as_str(&self) -> &str { |
412 | self |
413 | } |
414 | |
415 | /// Return a mutable string slice of the whole `ArrayString`. |
416 | pub fn as_mut_str(&mut self) -> &mut str { |
417 | self |
418 | } |
419 | |
420 | /// Return a raw pointer to the string's buffer. |
421 | pub fn as_ptr(&self) -> *const u8 { |
422 | self.xs.as_ptr() as *const u8 |
423 | } |
424 | |
425 | /// Return a raw mutable pointer to the string's buffer. |
426 | pub fn as_mut_ptr(&mut self) -> *mut u8 { |
427 | self.xs.as_mut_ptr() as *mut u8 |
428 | } |
429 | } |
430 | |
431 | impl<const CAP: usize> Deref for ArrayString<CAP> |
432 | { |
433 | type Target = str; |
434 | #[inline ] |
435 | fn deref(&self) -> &str { |
436 | unsafe { |
437 | let sl: &[u8] = slice::from_raw_parts(self.as_ptr(), self.len()); |
438 | str::from_utf8_unchecked(sl) |
439 | } |
440 | } |
441 | } |
442 | |
443 | impl<const CAP: usize> DerefMut for ArrayString<CAP> |
444 | { |
445 | #[inline ] |
446 | fn deref_mut(&mut self) -> &mut str { |
447 | unsafe { |
448 | let len: usize = self.len(); |
449 | let sl: &mut [u8] = slice::from_raw_parts_mut(self.as_mut_ptr(), len); |
450 | str::from_utf8_unchecked_mut(sl) |
451 | } |
452 | } |
453 | } |
454 | |
455 | impl<const CAP: usize> PartialEq for ArrayString<CAP> |
456 | { |
457 | fn eq(&self, rhs: &Self) -> bool { |
458 | **self == **rhs |
459 | } |
460 | } |
461 | |
462 | impl<const CAP: usize> PartialEq<str> for ArrayString<CAP> |
463 | { |
464 | fn eq(&self, rhs: &str) -> bool { |
465 | &**self == rhs |
466 | } |
467 | } |
468 | |
469 | impl<const CAP: usize> PartialEq<ArrayString<CAP>> for str |
470 | { |
471 | fn eq(&self, rhs: &ArrayString<CAP>) -> bool { |
472 | self == &**rhs |
473 | } |
474 | } |
475 | |
476 | impl<const CAP: usize> Eq for ArrayString<CAP> |
477 | { } |
478 | |
479 | impl<const CAP: usize> Hash for ArrayString<CAP> |
480 | { |
481 | fn hash<H: Hasher>(&self, h: &mut H) { |
482 | (**self).hash(state:h) |
483 | } |
484 | } |
485 | |
486 | impl<const CAP: usize> Borrow<str> for ArrayString<CAP> |
487 | { |
488 | fn borrow(&self) -> &str { self } |
489 | } |
490 | |
491 | impl<const CAP: usize> BorrowMut<str> for ArrayString<CAP> |
492 | { |
493 | fn borrow_mut(&mut self) -> &mut str { self } |
494 | } |
495 | |
496 | impl<const CAP: usize> AsRef<str> for ArrayString<CAP> |
497 | { |
498 | fn as_ref(&self) -> &str { self } |
499 | } |
500 | |
501 | impl<const CAP: usize> fmt::Debug for ArrayString<CAP> |
502 | { |
503 | fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { (**self).fmt(f) } |
504 | } |
505 | |
506 | #[cfg (feature="std" )] |
507 | impl<const CAP: usize> AsRef<Path> for ArrayString<CAP> { |
508 | fn as_ref(&self) -> &Path { |
509 | self.as_str().as_ref() |
510 | } |
511 | } |
512 | |
513 | impl<const CAP: usize> fmt::Display for ArrayString<CAP> |
514 | { |
515 | fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { (**self).fmt(f) } |
516 | } |
517 | |
518 | /// `Write` appends written data to the end of the string. |
519 | impl<const CAP: usize> fmt::Write for ArrayString<CAP> |
520 | { |
521 | fn write_char(&mut self, c: char) -> fmt::Result { |
522 | self.try_push(c).map_err(|_| fmt::Error) |
523 | } |
524 | |
525 | fn write_str(&mut self, s: &str) -> fmt::Result { |
526 | self.try_push_str(s).map_err(|_| fmt::Error) |
527 | } |
528 | } |
529 | |
530 | impl<const CAP: usize> Clone for ArrayString<CAP> |
531 | { |
532 | fn clone(&self) -> ArrayString<CAP> { |
533 | *self |
534 | } |
535 | fn clone_from(&mut self, rhs: &Self) { |
536 | // guaranteed to fit due to types matching. |
537 | self.clear(); |
538 | self.try_push_str(rhs).ok(); |
539 | } |
540 | } |
541 | |
542 | impl<const CAP: usize> PartialOrd for ArrayString<CAP> |
543 | { |
544 | fn partial_cmp(&self, rhs: &Self) -> Option<cmp::Ordering> { |
545 | (**self).partial_cmp(&**rhs) |
546 | } |
547 | fn lt(&self, rhs: &Self) -> bool { **self < **rhs } |
548 | fn le(&self, rhs: &Self) -> bool { **self <= **rhs } |
549 | fn gt(&self, rhs: &Self) -> bool { **self > **rhs } |
550 | fn ge(&self, rhs: &Self) -> bool { **self >= **rhs } |
551 | } |
552 | |
553 | impl<const CAP: usize> PartialOrd<str> for ArrayString<CAP> |
554 | { |
555 | fn partial_cmp(&self, rhs: &str) -> Option<cmp::Ordering> { |
556 | (**self).partial_cmp(rhs) |
557 | } |
558 | fn lt(&self, rhs: &str) -> bool { &**self < rhs } |
559 | fn le(&self, rhs: &str) -> bool { &**self <= rhs } |
560 | fn gt(&self, rhs: &str) -> bool { &**self > rhs } |
561 | fn ge(&self, rhs: &str) -> bool { &**self >= rhs } |
562 | } |
563 | |
564 | impl<const CAP: usize> PartialOrd<ArrayString<CAP>> for str |
565 | { |
566 | fn partial_cmp(&self, rhs: &ArrayString<CAP>) -> Option<cmp::Ordering> { |
567 | self.partial_cmp(&**rhs) |
568 | } |
569 | fn lt(&self, rhs: &ArrayString<CAP>) -> bool { self < &**rhs } |
570 | fn le(&self, rhs: &ArrayString<CAP>) -> bool { self <= &**rhs } |
571 | fn gt(&self, rhs: &ArrayString<CAP>) -> bool { self > &**rhs } |
572 | fn ge(&self, rhs: &ArrayString<CAP>) -> bool { self >= &**rhs } |
573 | } |
574 | |
575 | impl<const CAP: usize> Ord for ArrayString<CAP> |
576 | { |
577 | fn cmp(&self, rhs: &Self) -> cmp::Ordering { |
578 | (**self).cmp(&**rhs) |
579 | } |
580 | } |
581 | |
582 | impl<const CAP: usize> FromStr for ArrayString<CAP> |
583 | { |
584 | type Err = CapacityError; |
585 | |
586 | fn from_str(s: &str) -> Result<Self, Self::Err> { |
587 | Self::from(s).map_err(op:CapacityError::simplify) |
588 | } |
589 | } |
590 | |
591 | #[cfg (feature="serde" )] |
592 | /// Requires crate feature `"serde"` |
593 | impl<const CAP: usize> Serialize for ArrayString<CAP> |
594 | { |
595 | fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> |
596 | where S: Serializer |
597 | { |
598 | serializer.serialize_str(&*self) |
599 | } |
600 | } |
601 | |
602 | #[cfg (feature="serde" )] |
603 | /// Requires crate feature `"serde"` |
604 | impl<'de, const CAP: usize> Deserialize<'de> for ArrayString<CAP> |
605 | { |
606 | fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> |
607 | where D: Deserializer<'de> |
608 | { |
609 | use serde::de::{self, Visitor}; |
610 | use std::marker::PhantomData; |
611 | |
612 | struct ArrayStringVisitor<const CAP: usize>(PhantomData<[u8; CAP]>); |
613 | |
614 | impl<'de, const CAP: usize> Visitor<'de> for ArrayStringVisitor<CAP> { |
615 | type Value = ArrayString<CAP>; |
616 | |
617 | fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result { |
618 | write!(formatter, "a string no more than {} bytes long" , CAP) |
619 | } |
620 | |
621 | fn visit_str<E>(self, v: &str) -> Result<Self::Value, E> |
622 | where E: de::Error, |
623 | { |
624 | ArrayString::from(v).map_err(|_| E::invalid_length(v.len(), &self)) |
625 | } |
626 | |
627 | fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E> |
628 | where E: de::Error, |
629 | { |
630 | let s = str::from_utf8(v).map_err(|_| E::invalid_value(de::Unexpected::Bytes(v), &self))?; |
631 | |
632 | ArrayString::from(s).map_err(|_| E::invalid_length(s.len(), &self)) |
633 | } |
634 | } |
635 | |
636 | deserializer.deserialize_str(ArrayStringVisitor(PhantomData)) |
637 | } |
638 | } |
639 | |
640 | #[cfg (feature = "borsh" )] |
641 | /// Requires crate feature `"borsh"` |
642 | impl<const CAP: usize> borsh::BorshSerialize for ArrayString<CAP> { |
643 | fn serialize<W: borsh::io::Write>(&self, writer: &mut W) -> borsh::io::Result<()> { |
644 | <str as borsh::BorshSerialize>::serialize(&*self, writer) |
645 | } |
646 | } |
647 | |
648 | #[cfg (feature = "borsh" )] |
649 | /// Requires crate feature `"borsh"` |
650 | impl<const CAP: usize> borsh::BorshDeserialize for ArrayString<CAP> { |
651 | fn deserialize_reader<R: borsh::io::Read>(reader: &mut R) -> borsh::io::Result<Self> { |
652 | let len = <u32 as borsh::BorshDeserialize>::deserialize_reader(reader)? as usize; |
653 | if len > CAP { |
654 | return Err(borsh::io::Error::new( |
655 | borsh::io::ErrorKind::InvalidData, |
656 | format!("Expected a string no more than {} bytes long" , CAP), |
657 | )) |
658 | } |
659 | |
660 | let mut buf = [0u8; CAP]; |
661 | let buf = &mut buf[..len]; |
662 | reader.read_exact(buf)?; |
663 | |
664 | let s = str::from_utf8(&buf).map_err(|err| { |
665 | borsh::io::Error::new(borsh::io::ErrorKind::InvalidData, err.to_string()) |
666 | })?; |
667 | Ok(Self::from(s).unwrap()) |
668 | } |
669 | } |
670 | |
671 | impl<'a, const CAP: usize> TryFrom<&'a str> for ArrayString<CAP> |
672 | { |
673 | type Error = CapacityError<&'a str>; |
674 | |
675 | fn try_from(f: &'a str) -> Result<Self, Self::Error> { |
676 | let mut v: ArrayString = Self::new(); |
677 | v.try_push_str(f)?; |
678 | Ok(v) |
679 | } |
680 | } |
681 | |
682 | impl<'a, const CAP: usize> TryFrom<fmt::Arguments<'a>> for ArrayString<CAP> |
683 | { |
684 | type Error = CapacityError<fmt::Error>; |
685 | |
686 | fn try_from(f: fmt::Arguments<'a>) -> Result<Self, Self::Error> { |
687 | use fmt::Write; |
688 | let mut v: ArrayString = Self::new(); |
689 | v.write_fmt(f).map_err(|e: Error| CapacityError::new(element:e))?; |
690 | Ok(v) |
691 | } |
692 | } |
693 | |
694 | #[cfg (feature = "zeroize" )] |
695 | /// "Best efforts" zeroing of the `ArrayString`'s buffer when the `zeroize` feature is enabled. |
696 | /// |
697 | /// The length is set to 0, and the buffer is dropped and zeroized. |
698 | /// Cannot ensure that previous moves of the `ArrayString` did not leave values on the stack. |
699 | /// |
700 | /// ``` |
701 | /// use arrayvec::ArrayString; |
702 | /// use zeroize::Zeroize; |
703 | /// let mut string = ArrayString::<6>::from("foobar").unwrap(); |
704 | /// string.zeroize(); |
705 | /// assert_eq!(string.len(), 0); |
706 | /// unsafe { string.set_len(string.capacity()) }; |
707 | /// assert_eq!(&*string, "\0\0\0\0\0\0"); |
708 | /// ``` |
709 | impl<const CAP: usize> zeroize::Zeroize for ArrayString<CAP> { |
710 | fn zeroize(&mut self) { |
711 | // There are no elements to drop |
712 | self.clear(); |
713 | // Zeroize the backing array. |
714 | self.xs.zeroize(); |
715 | } |
716 | } |
717 | |