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// run-pass #![feature(macro_metavar_expr)] macro_rules! nested { ( $a:ident ) => { macro_rules! $a { ( $$( $b:ident ),* ) => { $$( macro_rules! $b { ( $$$$( $c:ident ),* ) => { $$$$( fn $c() -> &'static str { stringify!($c) } ),* }; } )* }; } }; } fn main() { nested!(a); a!(b); b!(c); assert_eq!(c(), "c"); }