Macro arc

macro_rules! arc {
    () => { ... };
    (if { $($p:tt)* } else { $($n:tt)* }) => { ... };
    ($($p:tt)*) => { ... };
}

Indicates that this target has access to a native implementation of Arc.

This macro passes the provided code because #[cfg(all(feature = "alloc", target_has_atomic = "ptr"))] is currently active.