pub fn gen_definitions(
    fix_dictionary: &Dictionary,
    settings: &Settings,
) -> StringExpand description
Generates const implementors of
IsFieldDefinition.
The generated module will contain:
- A generated code notice (generated_code_notice).
 enumdefinitions for FIX field types.- A constant implementor of
IsFieldDefinitionfor each FIX field. 
The Rust code will be free of any leading and trailing whitespace. An effort is made to provide good formatting, but users shouldn’t rely on it and assume that formatting might be bad.