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#![allow(clippy::assertions_on_result_states)]
use serde::de::{
Deserialize, Deserializer, EnumAccess, IgnoredAny, MapAccess, VariantAccess, Visitor,
};
use serde_json::json;
use std::fmt;
#[derive(Debug)]
pub enum Enum {
Variant {
#[allow(dead_code)]
x: u8,
},
}
impl<'de> Deserialize<'de> for Enum {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
struct EnumVisitor;
impl<'de> Visitor<'de> for EnumVisitor {
type Value = Enum;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("enum Enum")
}
fn visit_enum<A>(self, data: A) -> Result<Self::Value, A::Error>
where
A: EnumAccess<'de>,
{
let (IgnoredAny, variant) = data.variant()?;
variant.struct_variant(&["x"], self)
}
fn visit_map<A>(self, mut data: A) -> Result<Self::Value, A::Error>
where
A: MapAccess<'de>,
{
let mut x = 0;
if let Some((IgnoredAny, value)) = data.next_entry()? {
x = value;
}
Ok(Enum::Variant { x })
}
}
deserializer.deserialize_enum("Enum", &["Variant"], EnumVisitor)
}
}
#[test]
fn test() {
let s = r#" {"Variant":{"x":0,"y":0}} "#;
assert!(serde_json::from_str::<Enum>(s).is_err());
let j = json!({"Variant":{"x":0,"y":0}});
assert!(serde_json::from_value::<Enum>(j).is_err());
}