# `hash_standard_resize_policy` Interface

A resize policy which delegates operations to size and trigger policies.

Defined in: `hash_policy.hpp`

## Template Parameters

Parameter | Description | Default Value
    class Size_Policy
| Size policy type. | `hash_exponential_size_policy`
    class Trigger_Policy
| Trigger policy type. | `hash_load_check_resize_trigger`
    bool External_Size_Access
| Indicates whether physical sizes can be accessed externally. | `false`
    typename Size_Type
| Size type. | size_t

## Base Classes

Class | Derivation Type
    Size_Policy
| public
    Trigger_Policy
| public

## Public Types and Constants

### General Definitions

Type | Definition | Description
    size_type
    Size_Type
| Size type.

### Policy Definitions

Type | Definition | Description
    trigger_policy
    Trigger_Policy
| Trigger policy type.
    size_policy
    Size_Policy
| Size policy type.
    external_size_access
    External_Size_Access
| Indicates whether sizes can be accessed externally.

## Public Methods

### Constructors, Destructor, and Related

Method | Description
      hash_standard_resize_policy
      ()
| Default constructor.
      hash_standard_resize_policy
      (const Size_Policy &r_size_policy)
| constructor taking some policies `r_size_policy` will be copied by the `Size_Policy` object of this object.
      hash_standard_resize_policy
      (const Size_Policy &r_size_policy,
        const Trigger_Policy &r_trigger_policy)
| constructor taking some policies. `r_size_policy` will be copied by the `Size_Policy` object of this object. `r_trigger_policy` will be copied by the `Trigger_Policy` object of this object.
    virtual
      ~hash_standard_resize_policy
      ()
| Destructor.
    inline void
      swap
      (hash_standard_resize_policy &other)
| Swaps content.

### Policy Access Methods

Method | Description
    Size_Policy &
      get_size_policy
      ()
| Access to the `Size_Policy` object used.
    const Size_Policy &
      get_size_policy
      () const
| Const access to the `Size_Policy` object used.
    Trigger_Policy &
      get_trigger_policy
      ()
| Access to the `Trigger_Policy` object used.
    const Trigger_Policy &
      get_trigger_policy
      () const
| Access to the `Trigger_Policy` object used.

### Size Access Methods

These methods are available only if the external size parameter indicates that external size access is allowed.

Method | Description
    inline size_type
      get_actual_size
      () const
| Returns the actual size of the container. This method returns the number of entries (used and unused) in the container. It is different from the container's size method, which returns the number of used entries. Calling this method will not compile when `External_Size_Access` == `false`.
    void
      resize
      (size_type suggested_new_size)
| Resizes the container to `suggested_new_size`, a suggested size (the actual size will be determined by the `Size_Policy` object). Calling this method will not compile when `External_Size_Access` == `false`.

## Protected Methods

### Insert Search Notifications.

Notifications called during an insert operation.

Method | Description
    inline void
      notify_insert_search_start
      ()
| Notifies a search started.
    inline void
      notify_insert_search_collision
      ()
| Notifies a search encountered a collision.
    inline void
      notify_insert_search_end
      ()
| Notifies a search ended.

### Find Search Notifications.

Notifications called during a find operation.

Method | Description
    inline void
      notify_find_search_start
      ()
| Notifies a search started.
    inline void
      notify_find_search_collision
      ()
| Notifies a search encountered a collision.
    inline void
      notify_find_search_end
      ()
| Notifies a search ended.

### Erase Search Notifications.

Notifications called during an insert operation.

Method | Description
    inline void
      notify_erase_search_start
      ()
| Notifies a search started.
    inline void
      notify_erase_search_collision
      ()
| Notifies a search encountered a collision.
    inline void
      notify_erase_search_end
      ()
| Notifies a search ended.

### Content Change Notifications

Notifications called when the content of the table changes in a way that can affect the resize policy.

Method | Description
    inline void
      notify_inserted
      (size_type num_e)
| Notifies an element was inserted.
    inline void
      notify_erased
      (size_type num_e)
| Notifies an element was erased.
    void
      notify_cleared
      ()
| Notifies the table was cleared.

### Size Change Notifications

Notifications called when the table changes size.

Method | Description
    void
      notify_resized
      (size_type new_size)
| Notifies the table was resized to `new_size`.

### Queries

Called to query whether/how to resize.

Method | Description
    inline bool
      is_resize_needed
      () const
| Queries whether a resize is needed.
    size_type
      get_new_size
      (size_type size,
        size_type num_used_e) const
| Queries what the new `size` should be, when the container is resized naturally. The current size of the container is `size`, and the number of used entries within the container is `num_used_e`.

## Private Methods

### Overrides

Method | Description
    virtual void
      do_resize
      (size_type new_size)
| Resizes to `new_size`.