Template Class GeometryHierarchyMap

Class Documentation

template<typename value_t>
class Acts::GeometryHierarchyMap

Store values mapped into the geometry hierarchy.

The core functionality is to find an equivalent element, i.e. an identifier-value pair, for a given geometry identifier via 

auto it = container.find(GeometryIdentifier(...));
if (it != container.end()) {
    ...
}
Template Parameters

  • value_t: stored value type

Trailing zero levels of stored geometry identifiers are used as broadcast values to refer to higher-level objects within the geometry, e.g. a geometry identifier with vanishing approach and sensitive index identifies a layer. An entry will all geometry identifier levels set to zero acts as the global default value.

The container also supports range-based iteration over all stored elements 

for (const auto& element : container) {
    ...
}

and index-based access to stored elements and associated geometry identifiers 

GeometryIdentifier id3 = container.idAt(3);
const auto& element4 = container.valueAt(4);

Adding elements is potentially expensive as the internal lookup structure must be updated. In addition, modifying an element in-place could change its identifier which would also break the lookup. Thus, the container can not be modified after construction to prevent misuse.

Note

No guarantees are given for the element order when using range-based or index-based access. Any apparent ordering must be considered an implementation detail and might change.

Public Types

using InputElement = typename std::pair<GeometryIdentifier, value_t>

Combined geometry identifier and value element. Only used for input.

using Iterator = typename std::vector<value_t>::const_iterator
using Size = typename std::vector<value_t>::size_type
using Value = value_t

Public Functions

GeometryHierarchyMap(std::vector<InputElement> elements)

Construct the container from the given elements.

Parameters

  • elements: input elements (must be unique with respect to identifier)

GeometryHierarchyMap(std::initializer_list<InputElement> elements)

Construct the container from an initializer list.

Parameters

  • elements: input initializer list

GeometryHierarchyMap() = default
GeometryHierarchyMap(const GeometryHierarchyMap&) = default
GeometryHierarchyMap(GeometryHierarchyMap&&) = default
~GeometryHierarchyMap() = default
Iterator begin() const

Return an iterator pointing to the beginning of the stored values.

bool empty() const

Check if any elements are stored.

Iterator end() const

Return an iterator pointing to the end of the stored values.

Iterator find(GeometryIdentifier id) const

Find the most specific value for a given geometry identifier.

This can be either from the element matching exactly to the given geometry id, if it exists, or from the element for the next available higher level within the geometry hierachy.

Parameters

  • id: geometry identifier for which information is requested

Return Value

  • iterator: to an existing value

  • <tt>.end()</tt>: iterator if no matching element exists

GeometryIdentifier idAt(Size index) const

Access the geometry identifier for the i-th element with bounds check.

Exceptions

  • std::out_of_range: for invalid indices

GeometryHierarchyMap &operator=(const GeometryHierarchyMap&) = default
GeometryHierarchyMap &operator=(GeometryHierarchyMap&&) = default
Size size() const

Return the number of stored elements.

const Value &valueAt(Size index) const

Access the value of the i-th element in the container with bounds check.

Exceptions

  • std::out_of_range: for invalid indices