Function rustc_infer::infer::error_reporting::need_type_info::closure_return_type_suggestion

pub(in infer::error_reporting::need_type_info) fn closure_return_type_suggestion(
    span: Span, 
    err: &mut DiagnosticBuilder<'_>, 
    output: &FnRetTy<'_>, 
    body: &Body<'_>, 
    descr: &str, 
    name: &str, 
    ret: &str, 
    parent_name: Option<String>, 
    parent_descr: Option<&str>
)

Suggest giving an appropriate return type to a closure expression.