garde/rules/length/
bytes.rs

1//! Implemented by types for which we can retrieve the number of bytes.
2//!
3//! See also: [`chars` on `str`](https://doc.rust-lang.org/std/primitive.str.html#method.chars).
4
5use crate::error::Error;
6
7pub fn apply<T: Bytes>(v: &T, (min, max): (usize, usize)) -> Result<(), Error> {
8    v.validate_num_bytes(min, max)
9}
10
11pub trait Bytes {
12    fn validate_num_bytes(&self, min: usize, max: usize) -> Result<(), Error>;
13}
14
15impl<T: HasBytes> Bytes for T {
16    fn validate_num_bytes(&self, min: usize, max: usize) -> Result<(), Error> {
17        super::check_len(self.num_bytes(), min, max)
18    }
19}
20
21impl<T: Bytes> Bytes for Option<T> {
22    fn validate_num_bytes(&self, min: usize, max: usize) -> Result<(), Error> {
23        match self {
24            Some(v) => v.validate_num_bytes(min, max),
25            None => Ok(()),
26        }
27    }
28}
29
30pub trait HasBytes {
31    fn num_bytes(&self) -> usize;
32}
33
34macro_rules! impl_via_len {
35    ($(in<$lifetime:lifetime>)? $T:ty) => {
36        impl<$($lifetime)?> HasBytes for $T {
37            fn num_bytes(&self) -> usize {
38                self.len()
39            }
40        }
41    };
42}
43
44impl_via_len!(std::string::String);
45impl_via_len!(in<'a> &'a std::string::String);
46impl_via_len!(in<'a> &'a str);
47impl_via_len!(in<'a> std::borrow::Cow<'a, str>);
48impl_via_len!(std::rc::Rc<str>);
49impl_via_len!(std::sync::Arc<str>);
50impl_via_len!(std::boxed::Box<str>);
51impl_via_len!(in<'a> &'a [u8]);
52impl_via_len!(std::rc::Rc<[u8]>);
53impl_via_len!(std::sync::Arc<[u8]>);
54impl_via_len!(std::boxed::Box<[u8]>);
55impl_via_len!(std::vec::Vec<u8>);
56
57impl<const N: usize> HasBytes for [u8; N] {
58    fn num_bytes(&self) -> usize {
59        self.len()
60    }
61}
garde/rules/length/bytes.rs

garde/rules/length/
bytes.rs
