eros 0.5.0

Error handling that is precise, no boilerplate, ergonomic, context aware, and performant.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72

use std::{
    borrow::Cow,
    fmt::{self, Debug, Display},
};

/// An Error type that is just a message.
/// It can hold a string in either a static or owned form.
/// No unnecessary allocation for static strings compared to `String`.
#[derive(PartialEq, Eq, PartialOrd, Ord, Hash)]
pub enum StrError {
    Static(&'static str),
    Owned(String),
}

impl std::error::Error for StrError {}

impl StrError {
    pub fn as_str(&self) -> &str {
        match self {
            StrError::Static(s) => s,
            StrError::Owned(s) => s,
        }
    }
}

impl Debug for StrError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            StrError::Static(s) => f.write_str(&s),
            StrError::Owned(s) => f.write_str(&s),
        }
    }
}

impl Display for StrError {
    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            StrError::Static(s) => write!(formatter, "{}", s),
            StrError::Owned(s) => write!(formatter, "{}", s),
        }
    }
}

impl Clone for StrError {
    fn clone(&self) -> Self {
        match self {
            StrError::Static(s) => StrError::Static(s),
            StrError::Owned(s) => StrError::Owned(s.clone()),
        }
    }
}

impl From<&'static str> for StrError {
    fn from(s: &'static str) -> StrError {
        StrError::Static(s)
    }
}

impl From<String> for StrError {
    fn from(s: String) -> StrError {
        StrError::Owned(s)
    }
}

impl From<Cow<'static, str>> for StrError {
    fn from(s: Cow<'static, str>) -> StrError {
        match s {
            Cow::Borrowed(s) => StrError::Static(s),
            Cow::Owned(s) => StrError::Owned(s),
        }
    }
}