Returns true if there are no enabled callbacks.
Declared in <util/btcsignals.h>
[[nodiscard, requires_capability(0x7f9521bf82a8), requires_capability(0x7f9500a48178), requires_capability(0x7f951f8ebef8), requires_capability(0x7f950d443be8), requires_capability(0x7f95133b6428), requires_capability(0x7f95231b73b8), requires_capability(0x7f9516ce7c08), requires_capability(0x7f9503ad2058)]]
bool
empty() const;
true if no connected callback is currently enabled.
The return value should not be discarded.