pub fn is_direct_expn_of(span: Span, name: &str) -> Option<Span>Expand description
Returns the pre-expansion span if the span directly comes from an expansion
of the macro name.
The difference with is_expn_of is that in
foo!(bar!(42));42 is considered expanded from foo! and bar! by is_expn_of but only
from bar! by is_direct_expn_of.