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)] 111 macro_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] 123 macro_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::Error> 127 where 128 $v: $crate::de::Visitor<$l>, 129 { 130 $( 131 let _ = $arg; 132 )* 133 self.deserialize_any(visitor) 134 } 135 }; 136 } 137 138 #[doc(hidden)] 139 #[macro_export(local_inner_macros)] 140 macro_rules! forward_to_deserialize_any_helper { 141 (bool<$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