See for std::marker::Copy:

But when you click on [src]:
pub macro Copy($item:item) {
/* compiler built-in */
}
Or for proc_macro::quote!:

With source:
pub macro quote($($t:tt)*) {
/* compiler built-in */
}
Or for core::ready!, which is not a built-in:

pub macro ready($e:expr) {
match $e {
$crate::task::Poll::Ready(t) => t,
$crate::task::Poll::Pending => {
return $crate::task::Poll::Pending;
}
}
}
@rustbot modify labels: T-rustdoc C-bug
See for
std::marker::Copy:But when you click on
[src]:Or for
proc_macro::quote!:With source:
Or for
core::ready!, which is not a built-in:@rustbot modify labels: T-rustdoc C-bug