Attribute Macro uses_string_tables 

#[uses_string_tables]

Marks the impl block to enable string table tracking.

When applied to an impl block or individual method, automatically enables the STRING_TABLE_STATE interest flag so string tables are tracked during parsing.

Examples

#[observer]
#[uses_string_tables]
impl MyObs {
    // Now you can use #[on_string_table] handlers
}