FromAttrMain entry point. Derived via macro. Anything that can be parsed from one or multiple attributes.
AttributeNamedValues that can be parsed named, e.g. name(<value>), name = <value>, name (as flag).
This is the default parsing mode used for fields in derived FromAttr implementations.
AttributePositionalValues that can be parsed positionally, i.e., without a name, e.g. "literal", a + b, true.
When deriving FromAttr this is enabled via putting #[attr(positional)] on the field.
impl <T: AttributeValue> FromAttr for T
impl <T: AttributeValue> AttributeNamed for T
impl <T: AttributeValue + PositionalValue> AttributePositional for T
AttributeValue"positional", meta(<value>), key = <value>.
impl <T: AttributeMeta> AttributeValue for T
AttributeMetaValues in function or meta style attributes, i.e., meta(<value>).