# Interface Specifics

Following are the library's interface specifics. Short Tutorial is a short tutorial, and Concepts describes some concepts.

## Namespace

All code is enclosed in namespace `pb_ds`. Nested within this is namespace `detail`, which contains the parts of this library that are considered implementation details.

## Containers

### Associative Containers

1. `container_base` - abstract base class for associative containers.
2. Hash-based:
   1. `basic_hash_table` - abstract base class for hash-based containers
   2. `cc_hash_table` - concrete collision-chaining hash-based containers
   3. `gp_hash_table` - concrete (general) probing hash-based containers
3. Tree-based:
   1. `basic_tree` - abstract base class for tree and trie based containers
   2. `tree` - concrete base class for tree-based containers
   3. `trie` - concrete base class for trie-based containers
4. List-based:
   1. `list_update` - singly-linked list with update-policy container

### Priority Queues

1. `priority_queue` - priority queue

## Container Tags and Traits

### Container Tags

#### Common

1. `container_tag` - base class for data structure tags

#### Associative-Containers

1. `associative_container_tag` - base class for associative-container data structure tags
2. `basic_hash_tag` - base class for hash-based structure tags
3. `cc_hash_tag` - collision-chaining hash structure tag
4. `gp_hash_tag` - (general) probing hash structure tag
5. `basic_tree_tag` - base class for tree-like structure tags
6. `tree_tag` - base class for tree structure tags
7. `rb_tree_tag` - red-black tree structure tag/li>
8. `splay_tree_tag` - splay tree structure tag
9. `ov_tree_tag` - ordered-vector tree structure tag
10. `trie_tag` - trie structure tag
11. `pat_trie_tag` - PATRICIA trie structure tag
12. `list_update_tag` - list (with updates) structure tag

#### Priority-Queues

1. `priority_queue_tag` - base class for priority-queue data structure tags
2. `pairing_heap_tag` - pairing-heap structure tag.
3. `binomial_heap_tag` - binomial-heap structure tag
4. `rc_binomial_heap_tag` - redundant-counter binomial-heap (i.e., a heap where binomial trees form a sequence that is similar to a de-amortized bit-addition algorithm) structure tag
5. `binary_heap_tag` - binary heap (based on an array or an array of nodes) structure tag
6. `thin_heap_tag` - thin heap (an alternative [kt99fat_heaps] to Fibonacci heap) data structure tag.

### Invalidation-Guarantee Tags

1. `basic_invalidation_guarantee` - weakest invalidation guarantee
2. `point_invalidation_guarantee` - stronger invalidation guarantee
3. `range_invalidation_guarantee` - strongest invalidation guarantee

### Container Traits

1. `container_traits` - traits for determining underlying data structure properties

## Container Policy Classes

### Hash Policies

#### Hash and Probe Policies

1. Hash Functions:
   1. `null_hash_fn` - type indicating one-step range-hashing
2. Range-Hashing Functions:
   1. Sample range-hashing function - interface required of a range-hashing functor
   2. `direct_mask_range_hashing` - (bit) mask-based range hashing functor
   3. `direct_mod_range_hashing` - modulo-based range hashing functor
3. Probe Functions:
   1. Sample probe function - interface required of a probe functor
   2. `null_probe_fn` - type indicating one-step ranged-probe
   3. `linear_probe_fn` - linear-probe functor
   4. `quadratic_probe_fn`- quadratic-probe functor
4. Ranged-Hash Functions:
   1. Sample ranged-hash function - interface required of a ranged-hash functor
5. Ranged-Probe Functions:
   1. Sample ranged-probe function - interface required of a ranged-probe functor

#### Resize Policies

1. Resize Policies:
   1. Sample resize policy - interface required of a resize policy
   2. `hash_standard_resize_policy` - standard resize policy
2. Size Policies:
   1. Sample size policy - interface required of a size policy
   2. `hash_exponential_size_policy` - exponential size policy (typically used with (bit) mask range-hashing)
   3. `hash_prime_size_policy` - prime size policy (typically used with modulo range-hashing)
3. Trigger Policies:
   1. Sample trigger policy - interface required of a trigger policy
   2. `hash_load_check_resize_trigger` - trigger policy based on load checks
   3. `cc_hash_max_collision_check_resize_trigger` - trigger policy based on collision checks

### Tree Policies

#### Tree Node-Update Policies

1. Sample node updater policy - interface required of a tree node-updating functor
2. `null_tree_node_update` - null policy indicating no updates are required
3. `tree_order_statistics_node_update` - updater enabling order statistics queries

### Trie Policies

#### Trie Element-Access Traits

1. Sample element-access traits - interface required of element-access traits
2. `string_trie_e_access_traits` - String element-access traits

#### Trie Node-Update Policies

1. Sample node updater policy - interface required of a trie node updater
2. `null_trie_node_update` - null policy indicating no updates are required
3. `trie_prefix_search_node_update` - updater enabling prefix searches
4. `trie_order_statistics_node_update` - updater enabling order statistics queries

### List Policies

#### List Update Policies

1. Sample list update policy - interface required of a list update policy
2. `move_to_front_lu_policy` - move-to-front update algorithm
3. `counter_lu_policy` - counter update algorithm

### Mapped-Type Policies

1. `null_mapped_type` - data policy indicating that a container is a "set"

## Exceptions

1. `container_error` - base class for all policy-based data structure errors
2. `insert_error`
3. `join_error`
4. `resize_error`