Derive Macro EdifactCompositeSerialize 

#[derive(EdifactCompositeSerialize)]
{
    // Attributes available to this derive:
    #[edifact]
}

Available on crate feature derive only.

Derive edifact_rs::EdifactCompositeSerialize for a composite-element struct.

The mirror of EdifactCompositeDeserialize: field n is emitted as component n, None becomes an empty component, and any gap left by a component = N override is filled so later components keep their positions.

Limitations

Same as EdifactSerialize: named-field structs only, no generics, no lifetime parameters. Field types must be String or Option<String>.