apply_if/
lib.rs

1#![doc=include_str!("../README.md")]
2#![no_std]
3#[warn(missing_docs)]
4#[cfg(test)]
5mod test;
6
7pub trait ApplyIf {
8    /// Takes a closure, and calls it on ``self`` if ``cond`` is true.
9    ///
10    /// Equivalent to the following:
11    /// ```
12    /// # struct Foo;
13    /// # impl Foo {
14    /// # fn foo(self, cond: bool) -> Self {
15    /// # let f = |x| x;
16    /// if cond {
17    ///   f(self)
18    /// } else {
19    ///   self
20    /// }
21    /// # }}
22    /// ```
23    /// **Note** this method only works on sized objects
24    fn apply_if<F>(self, cond: bool, f: F) -> Self
25    where
26        Self: Sized,
27        F: FnOnce(Self) -> Self;
28
29    /// Takes a closure, and calls it a mutable reference to `Self`.
30    /// Use this method with the mutable builder pattern
31    ///
32    /// Equivalent to the following for `self : &mut Self`:
33    /// ```
34    /// # struct Foo;
35    /// # impl Foo {
36    /// # fn foo(&mut self, cond:bool) -> &mut Self {
37    /// # let f = |x| x;
38    /// if cond {
39    ///   f(self)
40    /// } else {
41    ///   self
42    /// }
43    /// # }}
44    /// ```
45    fn apply_if_mut<F>(&mut self, cond: bool, f: F) -> &mut Self
46    where
47        F: FnOnce(&mut Self) -> &mut Self;
48
49    /// Apply the closure only if the given optional argument contains
50    /// a value.
51    /// Use this method with the immutable builder pattern
52    ///
53    /// ```
54    /// # struct Foo;
55    /// # impl Foo {
56    /// # fn foo(self, cond:bool) -> Self {
57    /// # let f = |x,u| x;
58    /// # let optional_u = Some(1);
59    /// if let Some(u) = optional_u {
60    ///   f(self,u)
61    /// } else {
62    ///   self
63    /// }
64    /// # }}
65    /// ```
66    fn apply_if_some<F, U>(self, u: Option<U>, f: F) -> Self
67    where
68        Self: Sized,
69        F: FnOnce(Self, U) -> Self;
70
71    /// Apply the closure only if the given optional argument contains
72    /// a value.
73    /// Use this method with the mutable builder pattern
74    ///
75    /// ```
76    /// # struct Foo;
77    /// # impl Foo {
78    /// # fn foo(&mut self, cond:bool) -> &mut Self {
79    /// # let f = |x,u| x;
80    /// # let optional_u = Some(1);
81    /// if let Some(u) = optional_u {
82    ///   f(self,u)
83    /// } else {
84    ///   self
85    /// }
86    /// # }}
87    /// ```
88    fn apply_if_some_mut<F, U>(&mut self, u: Option<U>, f: F) -> &mut Self
89    where
90        F: FnOnce(&mut Self, U) -> &mut Self;
91}
92
93impl<T> ApplyIf for T {
94    #[inline]
95    fn apply_if<F: FnOnce(Self) -> Self>(self, cond: bool, f: F) -> Self
96    where
97        Self: Sized,
98    {
99        if cond {
100            f(self)
101        } else {
102            self
103        }
104    }
105
106    #[inline]
107    fn apply_if_mut<F>(&mut self, cond: bool, f: F) -> &mut Self
108    where
109        F: FnOnce(&mut Self) -> &mut Self,
110    {
111        if cond {
112            f(self)
113        } else {
114            self
115        }
116    }
117
118    #[inline]
119    fn apply_if_some<F, U>(self, u: Option<U>, f: F) -> Self
120    where
121        Self: Sized,
122        F: FnOnce(Self, U) -> Self,
123    {
124        if let Some(u) = u {
125            f(self, u)
126        } else {
127            self
128        }
129    }
130
131    #[inline]
132    fn apply_if_some_mut<F, U>(&mut self, u: Option<U>, f: F) -> &mut Self
133    where
134        F: FnOnce(&mut Self, U) -> &mut Self,
135    {
136        if let Some(u) = u {
137            f(self, u)
138        } else {
139            self
140        }
141    }
142}
apply_if/lib.rs

apply_if/
lib.rs
