try-drop 0.2.0

Batteries included error handling mechanisms for drops which can fail
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
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165

#[cfg(feature = "ds-adhoc-mut")]
mod fn_mut;

#[cfg(feature = "ds-adhoc-mut")]
pub use fn_mut::*;

use crate::{FallibleTryDropStrategy, TryDropStrategy};

/// A quick and dirty drop strategy which uses a function.
#[cfg_attr(
    feature = "derives",
    derive(Debug, Copy, Clone, Ord, PartialOrd, Eq, PartialEq, Hash, Default)
)]
#[cfg_attr(feature = "shrinkwraprs", derive(Shrinkwrap))]
#[cfg_attr(feature = "shrinkwraprs", shrinkwrap(mutable))]
pub struct AdHocDropStrategy<F: Fn(crate::Error)>(pub F);

impl<F: Fn(crate::Error)> AdHocDropStrategy<F> {
    /// Take the inner function.
    #[cfg(feature = "shrinkwraprs")]
    pub fn take(this: Self) -> F {
        this.0
    }
}

impl<F: Fn(crate::Error)> TryDropStrategy for AdHocDropStrategy<F> {
    fn handle_error(&self, error: crate::Error) {
        self.0(error)
    }
}

impl<F: Fn(crate::Error)> From<F> for AdHocDropStrategy<F> {
    fn from(f: F) -> Self {
        AdHocDropStrategy(f)
    }
}

/// Signifies that this type can be converted into an [`AdHocDropStrategy`].
pub trait IntoAdHocDropStrategy: Fn(crate::Error) + Sized {
    /// Convert this type into an [`AdHocDropStrategy`].
    fn into_drop_strategy(self) -> AdHocDropStrategy<Self> {
        AdHocDropStrategy(self)
    }
}

impl<T: Fn(crate::Error)> IntoAdHocDropStrategy for T {}

/// A quick and dirty fallible drop strategy which uses a function.
#[cfg_attr(
    feature = "derives",
    derive(Debug, Copy, Clone, Ord, PartialOrd, Eq, PartialEq, Hash, Default)
)]
#[cfg_attr(feature = "shrinkwraprs", derive(Shrinkwrap))]
#[cfg_attr(feature = "shrinkwraprs", shrinkwrap(mutable))]
pub struct AdHocFallibleDropStrategy<F, E>(pub F)
where
    F: Fn(crate::Error) -> Result<(), E>,
    E: Into<anyhow::Error>;

impl<F, E> AdHocFallibleDropStrategy<F, E>
where
    F: Fn(crate::Error) -> Result<(), E>,
    E: Into<anyhow::Error>,
{
    /// Take the inner function.
    #[cfg(feature = "shrinkwraprs")]
    pub fn take(this: Self) -> F {
        this.0
    }
}

impl<F, E> FallibleTryDropStrategy for AdHocFallibleDropStrategy<F, E>
where
    F: Fn(crate::Error) -> Result<(), E>,
    E: Into<anyhow::Error>,
{
    type Error = E;

    fn try_handle_error(&self, error: crate::Error) -> Result<(), Self::Error> {
        (self.0)(error)
    }
}

impl<F, E> From<F> for AdHocFallibleDropStrategy<F, E>
where
    F: Fn(crate::Error) -> Result<(), E>,
    E: Into<anyhow::Error>,
{
    fn from(f: F) -> Self {
        Self(f)
    }
}

/// Signifies that this type can be converted into an [`AdHocFallibleDropStrategy`].
pub trait IntoAdHocFallibleDropStrategy<E: Into<anyhow::Error>>:
    Fn(crate::Error) -> Result<(), E> + Sized
{
    /// Convert this type into an [`AdHocFallibleDropStrategy`].
    fn into_drop_strategy(self) -> AdHocFallibleDropStrategy<Self, E> {
        AdHocFallibleDropStrategy(self)
    }
}

impl<T, E> IntoAdHocFallibleDropStrategy<E> for T
where
    T: Fn(crate::Error) -> Result<(), E>,
    E: Into<anyhow::Error>,
{}

#[cfg(test)]
mod tests {
    use std::cell::Cell;
    use std::rc::Rc;
    use crate::drop_strategies::PanicDropStrategy;
    use crate::test_utils::fallible;
    use super::*;

    #[test]
    fn test_adhoc_drop_strategy() {
        let works = Rc::new(Cell::new(false));
        let w = Rc::clone(&works);
        let strategy = AdHocDropStrategy(move |_| w.set(true));
        crate::install_thread_local_handlers(strategy, PanicDropStrategy::DEFAULT);
        drop(fallible());
        assert!(works.get(), "the strategy should have worked");
    }

    #[test]
    fn test_into_adhoc_drop_strategy() {
        let works = Rc::new(Cell::new(false));
        let w = Rc::clone(&works);
        let strategy = move |_| w.set(true);
        let strategy = IntoAdHocDropStrategy::into_drop_strategy(strategy);
        crate::install_thread_local_handlers(strategy, PanicDropStrategy::DEFAULT);
        drop(fallible());
        assert!(works.get(), "the strategy should have worked");
    }

    #[test]
    fn test_adhoc_fallible_drop_strategy() {
        let works = Rc::new(Cell::new(false));
        let w = Rc::clone(&works);
        let strategy = AdHocFallibleDropStrategy::<_, crate::Error>(move |_| {
            w.set(true);
            Ok(())
        });
        crate::install_thread_local_handlers(strategy, PanicDropStrategy::DEFAULT);
        drop(fallible());
        assert!(works.get(), "the strategy should have worked");
    }

    #[test]
    fn test_into_adhoc_fallible_drop_strategy() {
        let works = Rc::new(Cell::new(false));
        let w = Rc::clone(&works);
        let strategy = move |_| {
            w.set(true);
            Ok::<_, crate::Error>(())
        };
        let strategy = IntoAdHocFallibleDropStrategy::into_drop_strategy(strategy);
        crate::install_thread_local_handlers(strategy, PanicDropStrategy::DEFAULT);
        drop(fallible());
        assert!(works.get(), "the strategy should have worked");
    }
}