1//! HTTP status codes
2//!
3//! This module contains HTTP-status code related structs an errors. The main
4//! type in this module is `StatusCode` which is not intended to be used through
5//! this module but rather the `http::StatusCode` type.
6//!
7//! # Examples
8//!
9//! ```
10//! use http::StatusCode;
11//!
12//! assert_eq!(StatusCode::from_u16(200).unwrap(), StatusCode::OK);
13//! assert_eq!(StatusCode::NOT_FOUND, 404);
14//! assert!(StatusCode::OK.is_success());
15//! ```
16
17use std::convert::TryFrom;
18use std::error::Error;
19use std::fmt;
20use std::num::NonZeroU16;
21use std::str::FromStr;
22
23/// An HTTP status code (`status-code` in RFC 9110 et al.).
24///
25/// Constants are provided for known status codes, including those in the IANA
26/// [HTTP Status Code Registry](
27/// https://www.iana.org/assignments/http-status-codes/http-status-codes.xhtml).
28///
29/// Status code values in the range 100-999 (inclusive) are supported by this
30/// type. Values in the range 100-599 are semantically classified by the most
31/// significant digit. See [`StatusCode::is_success`], etc. Values above 599
32/// are unclassified but allowed for legacy compatibility, though their use is
33/// discouraged. Applications may interpret such values as protocol errors.
34///
35/// # Examples
36///
37/// ```
38/// use http::StatusCode;
39///
40/// assert_eq!(StatusCode::from_u16(200).unwrap(), StatusCode::OK);
41/// assert_eq!(StatusCode::NOT_FOUND.as_u16(), 404);
42/// assert!(StatusCode::OK.is_success());
43/// ```
44#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
45pub struct StatusCode(NonZeroU16);
46
47/// A possible error value when converting a `StatusCode` from a `u16` or `&str`.
48///
49/// This error indicates that the supplied input was not a valid number, was less
50/// than 100, or was greater than 999.
51pub struct InvalidStatusCode {
52 _priv: (),
53}
54
55impl StatusCode {
56 /// Converts a u16 to a status code.
57 ///
58 /// The function validates the correctness of the supplied u16. It must be
59 /// greater or equal to 100 and less than 1000.
60 ///
61 /// # Example
62 ///
63 /// ```
64 /// use http::StatusCode;
65 ///
66 /// let ok = StatusCode::from_u16(200).unwrap();
67 /// assert_eq!(ok, StatusCode::OK);
68 ///
69 /// let err = StatusCode::from_u16(99);
70 /// assert!(err.is_err());
71 /// ```
72 #[inline]
73 pub fn from_u16(src: u16) -> Result<StatusCode, InvalidStatusCode> {
74 if !(100..1000).contains(&src) {
75 return Err(InvalidStatusCode::new());
76 }
77
78 NonZeroU16::new(src)
79 .map(StatusCode)
80 .ok_or_else(InvalidStatusCode::new)
81 }
82
83 /// Converts a `&[u8]` to a status code.
84 pub fn from_bytes(src: &[u8]) -> Result<StatusCode, InvalidStatusCode> {
85 if src.len() != 3 {
86 return Err(InvalidStatusCode::new());
87 }
88
89 let a = src[0].wrapping_sub(b'0') as u16;
90 let b = src[1].wrapping_sub(b'0') as u16;
91 let c = src[2].wrapping_sub(b'0') as u16;
92
93 if a == 0 || a > 9 || b > 9 || c > 9 {
94 return Err(InvalidStatusCode::new());
95 }
96
97 let status = (a * 100) + (b * 10) + c;
98 NonZeroU16::new(status)
99 .map(StatusCode)
100 .ok_or_else(InvalidStatusCode::new)
101 }
102
103 /// Returns the `u16` corresponding to this `StatusCode`.
104 ///
105 /// # Note
106 ///
107 /// This is the same as the `From<StatusCode>` implementation, but
108 /// included as an inherent method because that implementation doesn't
109 /// appear in rustdocs, as well as a way to force the type instead of
110 /// relying on inference.
111 ///
112 /// # Example
113 ///
114 /// ```
115 /// let status = http::StatusCode::OK;
116 /// assert_eq!(status.as_u16(), 200);
117 /// ```
118 #[inline]
119 pub const fn as_u16(&self) -> u16 {
120 self.0.get()
121 }
122
123 /// Returns a &str representation of the `StatusCode`
124 ///
125 /// The return value only includes a numerical representation of the
126 /// status code. The canonical reason is not included.
127 ///
128 /// # Example
129 ///
130 /// ```
131 /// let status = http::StatusCode::OK;
132 /// assert_eq!(status.as_str(), "200");
133 /// ```
134 #[inline]
135 pub fn as_str(&self) -> &str {
136 let offset = (self.0.get() - 100) as usize;
137 let offset = offset * 3;
138
139 // Invariant: self has checked range [100, 999] and CODE_DIGITS is
140 // ASCII-only, of length 900 * 3 = 2700 bytes
141
142 #[cfg(debug_assertions)]
143 {
144 &CODE_DIGITS[offset..offset + 3]
145 }
146
147 #[cfg(not(debug_assertions))]
148 unsafe {
149 CODE_DIGITS.get_unchecked(offset..offset + 3)
150 }
151 }
152
153 /// Get the standardised `reason-phrase` for this status code.
154 ///
155 /// This is mostly here for servers writing responses, but could potentially have application
156 /// at other times.
157 ///
158 /// The reason phrase is defined as being exclusively for human readers. You should avoid
159 /// deriving any meaning from it at all costs.
160 ///
161 /// Bear in mind also that in HTTP/2.0 and HTTP/3.0 the reason phrase is abolished from
162 /// transmission, and so this canonical reason phrase really is the only reason phrase you’ll
163 /// find.
164 ///
165 /// # Example
166 ///
167 /// ```
168 /// let status = http::StatusCode::OK;
169 /// assert_eq!(status.canonical_reason(), Some("OK"));
170 /// ```
171 pub fn canonical_reason(&self) -> Option<&'static str> {
172 canonical_reason(self.0.get())
173 }
174
175 /// Check if status is within 100-199.
176 #[inline]
177 pub fn is_informational(&self) -> bool {
178 (100..200).contains(&self.0.get())
179 }
180
181 /// Check if status is within 200-299.
182 #[inline]
183 pub fn is_success(&self) -> bool {
184 (200..300).contains(&self.0.get())
185 }
186
187 /// Check if status is within 300-399.
188 #[inline]
189 pub fn is_redirection(&self) -> bool {
190 (300..400).contains(&self.0.get())
191 }
192
193 /// Check if status is within 400-499.
194 #[inline]
195 pub fn is_client_error(&self) -> bool {
196 (400..500).contains(&self.0.get())
197 }
198
199 /// Check if status is within 500-599.
200 #[inline]
201 pub fn is_server_error(&self) -> bool {
202 (500..600).contains(&self.0.get())
203 }
204}
205
206impl fmt::Debug for StatusCode {
207 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
208 fmt::Debug::fmt(&self.0, f)
209 }
210}
211
212/// Formats the status code, *including* the canonical reason.
213///
214/// # Example
215///
216/// ```
217/// # use http::StatusCode;
218/// assert_eq!(format!("{}", StatusCode::OK), "200 OK");
219/// ```
220impl fmt::Display for StatusCode {
221 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
222 write!(
223 f,
224 "{} {}",
225 u16::from(*self),
226 self.canonical_reason().unwrap_or("<unknown status code>")
227 )
228 }
229}
230
231impl Default for StatusCode {
232 #[inline]
233 fn default() -> StatusCode {
234 StatusCode::OK
235 }
236}
237
238impl PartialEq<u16> for StatusCode {
239 #[inline]
240 fn eq(&self, other: &u16) -> bool {
241 self.as_u16() == *other
242 }
243}
244
245impl PartialEq<StatusCode> for u16 {
246 #[inline]
247 fn eq(&self, other: &StatusCode) -> bool {
248 *self == other.as_u16()
249 }
250}
251
252impl From<StatusCode> for u16 {
253 #[inline]
254 fn from(status: StatusCode) -> u16 {
255 status.0.get()
256 }
257}
258
259impl FromStr for StatusCode {
260 type Err = InvalidStatusCode;
261
262 fn from_str(s: &str) -> Result<StatusCode, InvalidStatusCode> {
263 StatusCode::from_bytes(src:s.as_ref())
264 }
265}
266
267impl<'a> From<&'a StatusCode> for StatusCode {
268 #[inline]
269 fn from(t: &'a StatusCode) -> Self {
270 t.to_owned()
271 }
272}
273
274impl<'a> TryFrom<&'a [u8]> for StatusCode {
275 type Error = InvalidStatusCode;
276
277 #[inline]
278 fn try_from(t: &'a [u8]) -> Result<Self, Self::Error> {
279 StatusCode::from_bytes(src:t)
280 }
281}
282
283impl<'a> TryFrom<&'a str> for StatusCode {
284 type Error = InvalidStatusCode;
285
286 #[inline]
287 fn try_from(t: &'a str) -> Result<Self, Self::Error> {
288 t.parse()
289 }
290}
291
292impl TryFrom<u16> for StatusCode {
293 type Error = InvalidStatusCode;
294
295 #[inline]
296 fn try_from(t: u16) -> Result<Self, Self::Error> {
297 StatusCode::from_u16(src:t)
298 }
299}
300
301macro_rules! status_codes {
302 (
303 $(
304 $(#[$docs:meta])*
305 ($num:expr, $konst:ident, $phrase:expr);
306 )+
307 ) => {
308 impl StatusCode {
309 $(
310 $(#[$docs])*
311 pub const $konst: StatusCode = StatusCode(unsafe { NonZeroU16::new_unchecked($num) });
312 )+
313
314 }
315
316 fn canonical_reason(num: u16) -> Option<&'static str> {
317 match num {
318 $(
319 $num => Some($phrase),
320 )+
321 _ => None
322 }
323 }
324 }
325}
326
327status_codes! {
328 /// 100 Continue
329 /// [[RFC9110, Section 15.2.1](https://datatracker.ietf.org/doc/html/rfc9110#section-15.2.1)]
330 (100, CONTINUE, "Continue");
331 /// 101 Switching Protocols
332 /// [[RFC9110, Section 15.2.2](https://datatracker.ietf.org/doc/html/rfc9110#section-15.2.2)]
333 (101, SWITCHING_PROTOCOLS, "Switching Protocols");
334 /// 102 Processing
335 /// [[RFC2518, Section 10.1](https://datatracker.ietf.org/doc/html/rfc2518#section-10.1)]
336 (102, PROCESSING, "Processing");
337
338 /// 200 OK
339 /// [[RFC9110, Section 15.3.1](https://datatracker.ietf.org/doc/html/rfc9110#section-15.3.1)]
340 (200, OK, "OK");
341 /// 201 Created
342 /// [[RFC9110, Section 15.3.2](https://datatracker.ietf.org/doc/html/rfc9110#section-15.3.2)]
343 (201, CREATED, "Created");
344 /// 202 Accepted
345 /// [[RFC9110, Section 15.3.3](https://datatracker.ietf.org/doc/html/rfc9110#section-15.3.3)]
346 (202, ACCEPTED, "Accepted");
347 /// 203 Non-Authoritative Information
348 /// [[RFC9110, Section 15.3.4](https://datatracker.ietf.org/doc/html/rfc9110#section-15.3.4)]
349 (203, NON_AUTHORITATIVE_INFORMATION, "Non Authoritative Information");
350 /// 204 No Content
351 /// [[RFC9110, Section 15.3.5](https://datatracker.ietf.org/doc/html/rfc9110#section-15.3.5)]
352 (204, NO_CONTENT, "No Content");
353 /// 205 Reset Content
354 /// [[RFC9110, Section 15.3.6](https://datatracker.ietf.org/doc/html/rfc9110#section-15.3.6)]
355 (205, RESET_CONTENT, "Reset Content");
356 /// 206 Partial Content
357 /// [[RFC9110, Section 15.3.7](https://datatracker.ietf.org/doc/html/rfc9110#section-15.3.7)]
358 (206, PARTIAL_CONTENT, "Partial Content");
359 /// 207 Multi-Status
360 /// [[RFC4918, Section 11.1](https://datatracker.ietf.org/doc/html/rfc4918#section-11.1)]
361 (207, MULTI_STATUS, "Multi-Status");
362 /// 208 Already Reported
363 /// [[RFC5842, Section 7.1](https://datatracker.ietf.org/doc/html/rfc5842#section-7.1)]
364 (208, ALREADY_REPORTED, "Already Reported");
365
366 /// 226 IM Used
367 /// [[RFC3229, Section 10.4.1](https://datatracker.ietf.org/doc/html/rfc3229#section-10.4.1)]
368 (226, IM_USED, "IM Used");
369
370 /// 300 Multiple Choices
371 /// [[RFC9110, Section 15.4.1](https://datatracker.ietf.org/doc/html/rfc9110#section-15.4.1)]
372 (300, MULTIPLE_CHOICES, "Multiple Choices");
373 /// 301 Moved Permanently
374 /// [[RFC9110, Section 15.4.2](https://datatracker.ietf.org/doc/html/rfc9110#section-15.4.2)]
375 (301, MOVED_PERMANENTLY, "Moved Permanently");
376 /// 302 Found
377 /// [[RFC9110, Section 15.4.3](https://datatracker.ietf.org/doc/html/rfc9110#section-15.4.3)]
378 (302, FOUND, "Found");
379 /// 303 See Other
380 /// [[RFC9110, Section 15.4.4](https://datatracker.ietf.org/doc/html/rfc9110#section-15.4.4)]
381 (303, SEE_OTHER, "See Other");
382 /// 304 Not Modified
383 /// [[RFC9110, Section 15.4.5](https://datatracker.ietf.org/doc/html/rfc9110#section-15.4.5)]
384 (304, NOT_MODIFIED, "Not Modified");
385 /// 305 Use Proxy
386 /// [[RFC9110, Section 15.4.6](https://datatracker.ietf.org/doc/html/rfc9110#section-15.4.6)]
387 (305, USE_PROXY, "Use Proxy");
388 /// 307 Temporary Redirect
389 /// [[RFC9110, Section 15.4.7](https://datatracker.ietf.org/doc/html/rfc9110#section-15.4.7)]
390 (307, TEMPORARY_REDIRECT, "Temporary Redirect");
391 /// 308 Permanent Redirect
392 /// [[RFC9110, Section 15.4.8](https://datatracker.ietf.org/doc/html/rfc9110#section-15.4.8)]
393 (308, PERMANENT_REDIRECT, "Permanent Redirect");
394
395 /// 400 Bad Request
396 /// [[RFC9110, Section 15.5.1](https://datatracker.ietf.org/doc/html/rfc9110#section-15.5.1)]
397 (400, BAD_REQUEST, "Bad Request");
398 /// 401 Unauthorized
399 /// [[RFC9110, Section 15.5.2](https://datatracker.ietf.org/doc/html/rfc9110#section-15.5.2)]
400 (401, UNAUTHORIZED, "Unauthorized");
401 /// 402 Payment Required
402 /// [[RFC9110, Section 15.5.3](https://datatracker.ietf.org/doc/html/rfc9110#section-15.5.3)]
403 (402, PAYMENT_REQUIRED, "Payment Required");
404 /// 403 Forbidden
405 /// [[RFC9110, Section 15.5.4](https://datatracker.ietf.org/doc/html/rfc9110#section-15.5.4)]
406 (403, FORBIDDEN, "Forbidden");
407 /// 404 Not Found
408 /// [[RFC9110, Section 15.5.5](https://datatracker.ietf.org/doc/html/rfc9110#section-15.5.5)]
409 (404, NOT_FOUND, "Not Found");
410 /// 405 Method Not Allowed
411 /// [[RFC9110, Section 15.5.6](https://datatracker.ietf.org/doc/html/rfc9110#section-15.5.6)]
412 (405, METHOD_NOT_ALLOWED, "Method Not Allowed");
413 /// 406 Not Acceptable
414 /// [[RFC9110, Section 15.5.7](https://datatracker.ietf.org/doc/html/rfc9110#section-15.5.7)]
415 (406, NOT_ACCEPTABLE, "Not Acceptable");
416 /// 407 Proxy Authentication Required
417 /// [[RFC9110, Section 15.5.8](https://datatracker.ietf.org/doc/html/rfc9110#section-15.5.8)]
418 (407, PROXY_AUTHENTICATION_REQUIRED, "Proxy Authentication Required");
419 /// 408 Request Timeout
420 /// [[RFC9110, Section 15.5.9](https://datatracker.ietf.org/doc/html/rfc9110#section-15.5.9)]
421 (408, REQUEST_TIMEOUT, "Request Timeout");
422 /// 409 Conflict
423 /// [[RFC9110, Section 15.5.10](https://datatracker.ietf.org/doc/html/rfc9110#section-15.5.10)]
424 (409, CONFLICT, "Conflict");
425 /// 410 Gone
426 /// [[RFC9110, Section 15.5.11](https://datatracker.ietf.org/doc/html/rfc9110#section-15.5.11)]
427 (410, GONE, "Gone");
428 /// 411 Length Required
429 /// [[RFC9110, Section 15.5.12](https://datatracker.ietf.org/doc/html/rfc9110#section-15.5.12)]
430 (411, LENGTH_REQUIRED, "Length Required");
431 /// 412 Precondition Failed
432 /// [[RFC9110, Section 15.5.13](https://datatracker.ietf.org/doc/html/rfc9110#section-15.5.13)]
433 (412, PRECONDITION_FAILED, "Precondition Failed");
434 /// 413 Payload Too Large
435 /// [[RFC9110, Section 15.5.14](https://datatracker.ietf.org/doc/html/rfc9110#section-15.5.14)]
436 (413, PAYLOAD_TOO_LARGE, "Payload Too Large");
437 /// 414 URI Too Long
438 /// [[RFC9110, Section 15.5.15](https://datatracker.ietf.org/doc/html/rfc9110#section-15.5.15)]
439 (414, URI_TOO_LONG, "URI Too Long");
440 /// 415 Unsupported Media Type
441 /// [[RFC9110, Section 15.5.16](https://datatracker.ietf.org/doc/html/rfc9110#section-15.5.16)]
442 (415, UNSUPPORTED_MEDIA_TYPE, "Unsupported Media Type");
443 /// 416 Range Not Satisfiable
444 /// [[RFC9110, Section 15.5.17](https://datatracker.ietf.org/doc/html/rfc9110#section-15.5.17)]
445 (416, RANGE_NOT_SATISFIABLE, "Range Not Satisfiable");
446 /// 417 Expectation Failed
447 /// [[RFC9110, Section 15.5.18](https://datatracker.ietf.org/doc/html/rfc9110#section-15.5.18)]
448 (417, EXPECTATION_FAILED, "Expectation Failed");
449 /// 418 I'm a teapot
450 /// [curiously not registered by IANA but [RFC2324, Section 2.3.2](https://datatracker.ietf.org/doc/html/rfc2324#section-2.3.2)]
451 (418, IM_A_TEAPOT, "I'm a teapot");
452
453 /// 421 Misdirected Request
454 /// [[RFC9110, Section 15.5.20](https://datatracker.ietf.org/doc/html/rfc9110#section-15.5.20)]
455 (421, MISDIRECTED_REQUEST, "Misdirected Request");
456 /// 422 Unprocessable Entity
457 /// [[RFC9110, Section 15.5.21](https://datatracker.ietf.org/doc/html/rfc9110#section-15.5.21)]
458 (422, UNPROCESSABLE_ENTITY, "Unprocessable Entity");
459 /// 423 Locked
460 /// [[RFC4918, Section 11.3](https://datatracker.ietf.org/doc/html/rfc4918#section-11.3)]
461 (423, LOCKED, "Locked");
462 /// 424 Failed Dependency
463 /// [[RFC4918, Section 11.4](https://tools.ietf.org/html/rfc4918#section-11.4)]
464 (424, FAILED_DEPENDENCY, "Failed Dependency");
465
466 /// 425 Too early
467 /// [[RFC8470, Section 5.2](https://httpwg.org/specs/rfc8470.html#status)]
468 (425, TOO_EARLY, "Too Early");
469
470 /// 426 Upgrade Required
471 /// [[RFC9110, Section 15.5.22](https://datatracker.ietf.org/doc/html/rfc9110#section-15.5.22)]
472 (426, UPGRADE_REQUIRED, "Upgrade Required");
473
474 /// 428 Precondition Required
475 /// [[RFC6585, Section 3](https://datatracker.ietf.org/doc/html/rfc6585#section-3)]
476 (428, PRECONDITION_REQUIRED, "Precondition Required");
477 /// 429 Too Many Requests
478 /// [[RFC6585, Section 4](https://datatracker.ietf.org/doc/html/rfc6585#section-4)]
479 (429, TOO_MANY_REQUESTS, "Too Many Requests");
480
481 /// 431 Request Header Fields Too Large
482 /// [[RFC6585, Section 5](https://datatracker.ietf.org/doc/html/rfc6585#section-5)]
483 (431, REQUEST_HEADER_FIELDS_TOO_LARGE, "Request Header Fields Too Large");
484
485 /// 451 Unavailable For Legal Reasons
486 /// [[RFC7725, Section 3](https://tools.ietf.org/html/rfc7725#section-3)]
487 (451, UNAVAILABLE_FOR_LEGAL_REASONS, "Unavailable For Legal Reasons");
488
489 /// 500 Internal Server Error
490 /// [[RFC9110, Section 15.6.1](https://datatracker.ietf.org/doc/html/rfc9110#section-15.6.1)]
491 (500, INTERNAL_SERVER_ERROR, "Internal Server Error");
492 /// 501 Not Implemented
493 /// [[RFC9110, Section 15.6.2](https://datatracker.ietf.org/doc/html/rfc9110#section-15.6.2)]
494 (501, NOT_IMPLEMENTED, "Not Implemented");
495 /// 502 Bad Gateway
496 /// [[RFC9110, Section 15.6.3](https://datatracker.ietf.org/doc/html/rfc9110#section-15.6.3)]
497 (502, BAD_GATEWAY, "Bad Gateway");
498 /// 503 Service Unavailable
499 /// [[RFC9110, Section 15.6.4](https://datatracker.ietf.org/doc/html/rfc9110#section-15.6.4)]
500 (503, SERVICE_UNAVAILABLE, "Service Unavailable");
501 /// 504 Gateway Timeout
502 /// [[RFC9110, Section 15.6.5](https://datatracker.ietf.org/doc/html/rfc9110#section-15.6.5)]
503 (504, GATEWAY_TIMEOUT, "Gateway Timeout");
504 /// 505 HTTP Version Not Supported
505 /// [[RFC9110, Section 15.6.6](https://datatracker.ietf.org/doc/html/rfc9110#section-15.6.6)]
506 (505, HTTP_VERSION_NOT_SUPPORTED, "HTTP Version Not Supported");
507 /// 506 Variant Also Negotiates
508 /// [[RFC2295, Section 8.1](https://datatracker.ietf.org/doc/html/rfc2295#section-8.1)]
509 (506, VARIANT_ALSO_NEGOTIATES, "Variant Also Negotiates");
510 /// 507 Insufficient Storage
511 /// [[RFC4918, Section 11.5](https://datatracker.ietf.org/doc/html/rfc4918#section-11.5)]
512 (507, INSUFFICIENT_STORAGE, "Insufficient Storage");
513 /// 508 Loop Detected
514 /// [[RFC5842, Section 7.2](https://datatracker.ietf.org/doc/html/rfc5842#section-7.2)]
515 (508, LOOP_DETECTED, "Loop Detected");
516
517 /// 510 Not Extended
518 /// [[RFC2774, Section 7](https://datatracker.ietf.org/doc/html/rfc2774#section-7)]
519 (510, NOT_EXTENDED, "Not Extended");
520 /// 511 Network Authentication Required
521 /// [[RFC6585, Section 6](https://datatracker.ietf.org/doc/html/rfc6585#section-6)]
522 (511, NETWORK_AUTHENTICATION_REQUIRED, "Network Authentication Required");
523}
524
525impl InvalidStatusCode {
526 fn new() -> InvalidStatusCode {
527 InvalidStatusCode { _priv: () }
528 }
529}
530
531impl fmt::Debug for InvalidStatusCode {
532 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
533 fDebugStruct<'_, '_>.debug_struct(name:"InvalidStatusCode")
534 // skip _priv noise
535 .finish()
536 }
537}
538
539impl fmt::Display for InvalidStatusCode {
540 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
541 f.write_str(data:"invalid status code")
542 }
543}
544
545impl Error for InvalidStatusCode {}
546
547// A string of packed 3-ASCII-digit status code values for the supported range
548// of [100, 999] (900 codes, 2700 bytes).
549const CODE_DIGITS: &str = "\
550100101102103104105106107108109110111112113114115116117118119\
551120121122123124125126127128129130131132133134135136137138139\
552140141142143144145146147148149150151152153154155156157158159\
553160161162163164165166167168169170171172173174175176177178179\
554180181182183184185186187188189190191192193194195196197198199\
555200201202203204205206207208209210211212213214215216217218219\
556220221222223224225226227228229230231232233234235236237238239\
557240241242243244245246247248249250251252253254255256257258259\
558260261262263264265266267268269270271272273274275276277278279\
559280281282283284285286287288289290291292293294295296297298299\
560300301302303304305306307308309310311312313314315316317318319\
561320321322323324325326327328329330331332333334335336337338339\
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