1// Super explicit first paragraph because this shows up at the top level and
2// trips up people who are just looking for basic Serialize / Deserialize
3// documentation.
4//
5/// Helper macro when implementing the `Deserializer` part of a new data format
6/// for Serde.
7///
8/// Some [`Deserializer`] implementations for self-describing formats do not
9/// care what hint the [`Visitor`] gives them, they just want to blindly call
10/// the [`Visitor`] method corresponding to the data they can tell is in the
11/// input. This requires repetitive implementations of all the [`Deserializer`]
12/// trait methods.
13///
14/// ```edition2021
15/// # use serde::forward_to_deserialize_any;
16/// # use serde::de::{value, Deserializer, Visitor};
17/// #
18/// # struct MyDeserializer;
19/// #
20/// # impl<'de> Deserializer<'de> for MyDeserializer {
21/// # type Error = value::Error;
22/// #
23/// # fn deserialize_any<V>(self, _: V) -> Result<V::Value, Self::Error>
24/// # where
25/// # V: Visitor<'de>,
26/// # {
27/// # unimplemented!()
28/// # }
29/// #
30/// #[inline]
31/// fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value, Self::Error>
32/// where
33/// V: Visitor<'de>,
34/// {
35/// self.deserialize_any(visitor)
36/// }
37/// #
38/// # forward_to_deserialize_any! {
39/// # i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
40/// # bytes byte_buf option unit unit_struct newtype_struct seq tuple
41/// # tuple_struct map struct enum identifier ignored_any
42/// # }
43/// # }
44/// ```
45///
46/// The `forward_to_deserialize_any!` macro implements these simple forwarding
47/// methods so that they forward directly to [`Deserializer::deserialize_any`].
48/// You can choose which methods to forward.
49///
50/// ```edition2021
51/// # use serde::forward_to_deserialize_any;
52/// # use serde::de::{value, Deserializer, Visitor};
53/// #
54/// # struct MyDeserializer;
55/// #
56/// impl<'de> Deserializer<'de> for MyDeserializer {
57/// # type Error = value::Error;
58/// #
59/// fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>
60/// where
61/// V: Visitor<'de>,
62/// {
63/// /* ... */
64/// # let _ = visitor;
65/// # unimplemented!()
66/// }
67///
68/// forward_to_deserialize_any! {
69/// bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
70/// bytes byte_buf option unit unit_struct newtype_struct seq tuple
71/// tuple_struct map struct enum identifier ignored_any
72/// }
73/// }
74/// ```
75///
76/// The macro assumes the convention that your `Deserializer` lifetime parameter
77/// is called `'de` and that the `Visitor` type parameters on each method are
78/// called `V`. A different type parameter and a different lifetime can be
79/// specified explicitly if necessary.
80///
81/// ```edition2021
82/// # use serde::forward_to_deserialize_any;
83/// # use serde::de::{value, Deserializer, Visitor};
84/// # use std::marker::PhantomData;
85/// #
86/// # struct MyDeserializer<V>(PhantomData<V>);
87/// #
88/// # impl<'q, V> Deserializer<'q> for MyDeserializer<V> {
89/// # type Error = value::Error;
90/// #
91/// # fn deserialize_any<W>(self, visitor: W) -> Result<W::Value, Self::Error>
92/// # where
93/// # W: Visitor<'q>,
94/// # {
95/// # unimplemented!()
96/// # }
97/// #
98/// forward_to_deserialize_any! {
99/// <W: Visitor<'q>>
100/// bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
101/// bytes byte_buf option unit unit_struct newtype_struct seq tuple
102/// tuple_struct map struct enum identifier ignored_any
103/// }
104/// # }
105/// ```
106///
107/// [`Deserializer`]: trait.Deserializer.html
108/// [`Visitor`]: de/trait.Visitor.html
109/// [`Deserializer::deserialize_any`]: trait.Deserializer.html#tymethod.deserialize_any
110#[macro_export(local_inner_macros)]
111macro_rules! forward_to_deserialize_any {
112 (<$visitor:ident: Visitor<$lifetime:tt>> $($func:ident)*) => {
113 $(forward_to_deserialize_any_helper!{$func<$lifetime, $visitor>})*
114 };
115 // This case must be after the previous one.
116 ($($func:ident)*) => {
117 $(forward_to_deserialize_any_helper!{$func<'de, V>})*
118 };
119}
120
121#[doc(hidden)]
122#[macro_export]
123macro_rules! forward_to_deserialize_any_method {
124 ($func:ident<$l:tt, $v:ident>($($arg:ident : $ty:ty),*)) => {
125 #[inline]
126 fn $func<$v>(self, $($arg: $ty,)* visitor: $v) -> $crate::__private::Result<$v::Value, <Self as $crate::de::Deserializer<$l>>::Error>
127 where
128 $v: $crate::de::Visitor<$l>,
129 {
130 $(
131 let _ = $arg;
132 )*
133 self.deserialize_any(visitor)
134 }
135 };
136}
137
138#[doc(hidden)]
139#[macro_export(local_inner_macros)]
140macro_rules! forward_to_deserialize_any_helper {
141 (bool<$l:tt, $v:ident>) => {
142 forward_to_deserialize_any_method!{deserialize_bool<$l, $v>()}
143 };
144 (i8<$l:tt, $v:ident>) => {
145 forward_to_deserialize_any_method!{deserialize_i8<$l, $v>()}
146 };
147 (i16<$l:tt, $v:ident>) => {
148 forward_to_deserialize_any_method!{deserialize_i16<$l, $v>()}
149 };
150 (i32<$l:tt, $v:ident>) => {
151 forward_to_deserialize_any_method!{deserialize_i32<$l, $v>()}
152 };
153 (i64<$l:tt, $v:ident>) => {
154 forward_to_deserialize_any_method!{deserialize_i64<$l, $v>()}
155 };
156 (i128<$l:tt, $v:ident>) => {
157 forward_to_deserialize_any_method!{deserialize_i128<$l, $v>()}
158 };
159 (u8<$l:tt, $v:ident>) => {
160 forward_to_deserialize_any_method!{deserialize_u8<$l, $v>()}
161 };
162 (u16<$l:tt, $v:ident>) => {
163 forward_to_deserialize_any_method!{deserialize_u16<$l, $v>()}
164 };
165 (u32<$l:tt, $v:ident>) => {
166 forward_to_deserialize_any_method!{deserialize_u32<$l, $v>()}
167 };
168 (u64<$l:tt, $v:ident>) => {
169 forward_to_deserialize_any_method!{deserialize_u64<$l, $v>()}
170 };
171 (u128<$l:tt, $v:ident>) => {
172 forward_to_deserialize_any_method!{deserialize_u128<$l, $v>()}
173 };
174 (f32<$l:tt, $v:ident>) => {
175 forward_to_deserialize_any_method!{deserialize_f32<$l, $v>()}
176 };
177 (f64<$l:tt, $v:ident>) => {
178 forward_to_deserialize_any_method!{deserialize_f64<$l, $v>()}
179 };
180 (char<$l:tt, $v:ident>) => {
181 forward_to_deserialize_any_method!{deserialize_char<$l, $v>()}
182 };
183 (str<$l:tt, $v:ident>) => {
184 forward_to_deserialize_any_method!{deserialize_str<$l, $v>()}
185 };
186 (string<$l:tt, $v:ident>) => {
187 forward_to_deserialize_any_method!{deserialize_string<$l, $v>()}
188 };
189 (bytes<$l:tt, $v:ident>) => {
190 forward_to_deserialize_any_method!{deserialize_bytes<$l, $v>()}
191 };
192 (byte_buf<$l:tt, $v:ident>) => {
193 forward_to_deserialize_any_method!{deserialize_byte_buf<$l, $v>()}
194 };
195 (option<$l:tt, $v:ident>) => {
196 forward_to_deserialize_any_method!{deserialize_option<$l, $v>()}
197 };
198 (unit<$l:tt, $v:ident>) => {
199 forward_to_deserialize_any_method!{deserialize_unit<$l, $v>()}
200 };
201 (unit_struct<$l:tt, $v:ident>) => {
202 forward_to_deserialize_any_method!{deserialize_unit_struct<$l, $v>(name: &'static str)}
203 };
204 (newtype_struct<$l:tt, $v:ident>) => {
205 forward_to_deserialize_any_method!{deserialize_newtype_struct<$l, $v>(name: &'static str)}
206 };
207 (seq<$l:tt, $v:ident>) => {
208 forward_to_deserialize_any_method!{deserialize_seq<$l, $v>()}
209 };
210 (tuple<$l:tt, $v:ident>) => {
211 forward_to_deserialize_any_method!{deserialize_tuple<$l, $v>(len: usize)}
212 };
213 (tuple_struct<$l:tt, $v:ident>) => {
214 forward_to_deserialize_any_method!{deserialize_tuple_struct<$l, $v>(name: &'static str, len: usize)}
215 };
216 (map<$l:tt, $v:ident>) => {
217 forward_to_deserialize_any_method!{deserialize_map<$l, $v>()}
218 };
219 (struct<$l:tt, $v:ident>) => {
220 forward_to_deserialize_any_method!{deserialize_struct<$l, $v>(name: &'static str, fields: &'static [&'static str])}
221 };
222 (enum<$l:tt, $v:ident>) => {
223 forward_to_deserialize_any_method!{deserialize_enum<$l, $v>(name: &'static str, variants: &'static [&'static str])}
224 };
225 (identifier<$l:tt, $v:ident>) => {
226 forward_to_deserialize_any_method!{deserialize_identifier<$l, $v>()}
227 };
228 (ignored_any<$l:tt, $v:ident>) => {
229 forward_to_deserialize_any_method!{deserialize_ignored_any<$l, $v>()}
230 };
231}
232