Trait erased_serde::Serialize
source · [−]pub trait Serialize {
fn erased_serialize(&self, v: &mut dyn Serializer) -> Result<Ok, Error>;
}Expand description
An object-safe equivalent of Serde’s Serialize trait.
Any implementation of Serde’s Serialize converts seamlessly to an
&erased_serde::Serialize or Box<erased_serde::Serialize> trait object.
use erased_serde::{Serialize, Serializer};
use std::collections::BTreeMap as Map;
use std::io;
fn main() {
// Construct some serializers.
let json = &mut serde_json::Serializer::new(io::stdout());
let cbor = &mut serde_cbor::Serializer::new(serde_cbor::ser::IoWrite::new(io::stdout()));
// The values in this map are boxed trait objects. Ordinarily this would not
// be possible with serde::Serializer because of object safety, but type
// erasure makes it possible with erased_serde::Serializer.
let mut formats: Map<&str, Box<dyn Serializer>> = Map::new();
formats.insert("json", Box::new(<dyn Serializer>::erase(json)));
formats.insert("cbor", Box::new(<dyn Serializer>::erase(cbor)));
// These are boxed trait objects as well. Same thing here - type erasure
// makes this possible.
let mut values: Map<&str, Box<dyn Serialize>> = Map::new();
values.insert("vec", Box::new(vec!["a", "b"]));
values.insert("int", Box::new(65536));
// Pick a Serializer out of the formats map.
let format = formats.get_mut("json").unwrap();
// Pick a Serialize out of the values map.
let value = values.get("vec").unwrap();
// This line prints `["a","b"]` to stdout.
value.erased_serialize(format).unwrap();
}