azul_css_parser/
macros.rs

1/// Implement `Display` for an enum.
2///
3/// Example usage:
4/// ```
5/// enum Foo<'a> {
6///     Bar(&'a str)
7///     Baz(i32)
8/// }
9///
10/// impl_display!{ Foo<'a>, {
11///     Bar(s) => s,
12///     Baz(i) => format!("{}", i)
13/// }}
14/// ```
15macro_rules! impl_display {
16    // For a type with a lifetime
17    ($enum:ident<$lt:lifetime>, {$($variant:pat => $fmt_string:expr),+$(,)* }) => {
18
19        impl<$lt> ::std::fmt::Display for $enum<$lt> {
20            fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
21                use self::$enum::*;
22                match &self {
23                    $(
24                        $variant => write!(f, "{}", $fmt_string),
25                    )+
26                }
27            }
28        }
29
30    };
31
32    // For a type without a lifetime
33    ($enum:ident, {$($variant:pat => $fmt_string:expr),+$(,)* }) => {
34
35        impl ::std::fmt::Display for $enum {
36            fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
37                use self::$enum::*;
38                match &self {
39                    $(
40                        $variant => write!(f, "{}", $fmt_string),
41                    )+
42                }
43            }
44        }
45
46    };
47}
48
49/// Implements `Debug` to use `Display` instead - assumes the that the type has implemented `Display`
50macro_rules! impl_debug_as_display {
51    // For a type with a lifetime
52    ($enum:ident<$lt:lifetime>) => {
53
54        impl<$lt> ::std::fmt::Debug for $enum<$lt> {
55            fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
56                write!(f, "{}", self)
57            }
58        }
59
60    };
61
62    // For a type without a lifetime
63    ($enum:ident) => {
64
65        impl ::std::fmt::Debug for $enum {
66            fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
67                write!(f, "{}", self)
68            }
69        }
70
71    };
72}
73
74/// Implement the `From` trait for any type.
75/// Example usage:
76/// ```
77/// enum MyError<'a> {
78///     Bar(BarError<'a>)
79///     Foo(FooError<'a>)
80/// }
81///
82/// impl_from!(BarError<'a>, Error::Bar);
83/// impl_from!(BarError<'a>, Error::Bar);
84///
85/// ```
86macro_rules! impl_from {
87    // From a type with a lifetime to a type which also has a lifetime
88    ($a:ident<$c:lifetime>, $b:ident::$enum_type:ident) => {
89        impl<$c> From<$a<$c>> for $b<$c> {
90            fn from(e: $a<$c>) -> Self {
91                $b::$enum_type(e)
92            }
93        }
94    };
95
96    // From a type without a lifetime to a type which also does not have a lifetime
97    ($a:ident, $b:ident::$enum_type:ident) => {
98        impl From<$a> for $b {
99            fn from(e: $a) -> Self {
100                $b::$enum_type(e)
101            }
102        }
103    };
104}
azul_css_parser/macros.rs

azul_css_parser/
macros.rs
