#[serde(flatten)] doesn't work with #[serde(default)] for externally tagged enums #1626
Description
Given this:
#[derive(Deserialize, Debug)]
enum SomeEnum {
A(u32),
B(u32),
}
impl Default for SomeEnum {
fn default() -> Self {
SomeEnum::B(1)
}
}
#[derive(Deserialize, Debug)]
struct SomeStruct {
filler: u32,
#[serde(default)]
#[serde(flatten)]
some_enum: SomeEnum,
}trying to deserialize this yaml:
filler: 1into SomeStruct panics with a message:
no variant of enum SomeEnum found in flattened data
I hoped it would pick up the default value specified for SomeEnum instead...
Is this a bug or is this not supported?
Docs don't cover this, I tried searching issues, but couldn't find anything quite like this.