Macro remove_sections_inner

macro_rules! remove_sections_inner {
    ([$($stack:tt)*]) => { ... };
    ([$($stack:tt)*] @escape $_x:tt $($t:tt)*) => { ... };
    ([$($stack:tt)*] @section $x:ident $($t:tt)*) => { ... };
    ([$($stack:tt)*] $t:tt $($tail:tt)*) => { ... };
}