pub trait TopologyCounts: TopologyBase {
// Required methods
fn element_count(&self) -> usize;
fn relation_count(&self) -> usize;
}Expand description
Count capability for a topology view.
This trait is separated from TopologyBase because counts are a capability.
Some views can report global counts cheaply; others expose only local,
paged, generated, or filtered topology and should define counts only when the
result is meaningful for that view.
§Performance
Methods should be O(1) unless an implementation documents a weaker
contract.
Required Methods§
Sourcefn element_count(&self) -> usize
fn element_count(&self) -> usize
Returns the number of elements visible in this topology view.
§Performance
Expected O(1) unless the implementation documents otherwise.
Sourcefn relation_count(&self) -> usize
fn relation_count(&self) -> usize
Returns the number of relations visible in this topology view.
§Performance
Expected O(1) unless the implementation documents otherwise.
Dyn Compatibility§
This trait is dyn compatible.
In older versions of Rust, dyn compatibility was called "object safety".