Concurrently safe modifiers#

All methods in this section can be executed concurrently with each other and lookup methods.

Inserting values#

bool insert( const_accessor& result, const key_type& key );

bool insert( accessor& result, const key_type& key );

If the result accessor is not empty, releases the result and attempts to insert the value constructed from key, mapped_type() into the container.

Sets the result to provide access to the inserted element or to the element with equal key, which was already presented in the container.

Requirements:

  • the value_type type must meet the EmplaceConstructible requirements described in the [container.requirements] section of the ISO C++ Standard.

  • the mapped_type type must meet the DefaultConstructible requirements described in the [defaultconstructible] section of the ISO C++ Standard.

Returns: true if an element is inserted; false otherwise.

template <typename K>
bool insert( const_accessor& result, const K& key );

template <typename K>
bool insert( accessor& result, const K& key );

If the result accessor is not empty, releases the result and attempts to insert the value constructed from key, mapped_type() into the container.

Sets the result to provide access to the inserted element or to the element with the key, that compares equivalent to the value key, which was already presented in the container.

This overload only participates in the overload resolution if:

  • qualified-id hash_compare_type::is_transparent is valid and denotes a type

  • std::is_constructible<key_type, const K&>::value is true

Requirements: the mapped_type type must meet the DefaultConstructible requirements described in the [defaultconstructible] section of the ISO C++ Standard.

Returns: true if an element is inserted; false otherwise.

bool insert( const_accessor& result, const value_type& value );

bool insert( accessor& result, const value_type& value );

If the result accessor is not empty, releases the result and attempts to insert the value value into the container.

Sets the result to provide access to the inserted element or to the element with equal key, which was already presented in the container.

Requirements: the value_type type must meet the CopyInsertable requirements described in the [container.requirements] section of the ISO C++ Standard.

Returns: true if an element is inserted; false otherwise.

bool insert( const value_type& value );

Attempts to insert the value value into the container.

Requirements: the value_type type must meet the CopyInsertable requirements described in the [container.requirements] section of the ISO C++ Standard.

Returns: true if an element is inserted; false otherwise.

bool insert( const_accessor& result, value_type&& value );

bool insert( accessor& result, value_type&& value );

If the result accessor is not empty, releases the result and attempts to insert the value value into the container using move semantics.

Sets the result to provide access to the inserted element or to the element with equal key, which was already presented in the container.

value is left in a valid, but unspecified state.

Requirements: the value_type type must meet the MoveInsertable requirements described in the [container.requirements] section of the ISO C++ Standard.

Returns: true if an element is inserted; false otherwise.

bool insert( value_type&& value );

Attempts to insert the value value into the container using move semantics.

Requirements: the value_type type must meet the MoveInsertable requirements described in the [container.requirements] section of the ISO C++ Standard.

Returns: true if an element is inserted; false otherwise.

Inserting sequences of elements#

template <typename InputIterator>
void insert( InputIterator first, InputIterator last );

Attempts to insert all items from the half-open interval [first, last) into the container.

If the interval [first, last) contains multiple elements with equal keys, it is unspecified which element should be inserted.

Requirements: the InputIterator type must meet the requirements of InputIterator described in the [input.iterators] section of the ISO C++ Standard.

void insert( std::initializer_list<value_type> init );

Equivalent to insert(init.begin(), init.end()).

Emplacing elements#

template <typename... Args>
bool emplace( const_accessor& result, Args&&... args );

template <typename... Args>
bool emplace( accessor& result, Args&&... args );

If the result accessor is not empty, releases the result and attempts to insert an element constructed in-place from args into the container.

Sets the result to provide access to the inserted element or to the element with equal key, which was already presented in the container.

Requirements: the type value_type must meet the EmplaceConstructible requirements described in the [container.requirements] section of the ISO C++ Standard.

Returns: true if an element is inserted; false otherwise

template <typename... Args>
bool emplace( Args&&... args );

Attempts to insert an element constructed in-place from args into the container.

Requirements: the type value_type must meet the EmplaceConstructible requirements described in the [container.requirements] section of the ISO C++ Standard.

Returns: true if an element is inserted; false otherwise

Erasing elements#

bool erase( const key_type& key );

If an element with the key equivalent to key exists, removes it from the container.

Returns: true if an element is removed; false otherwise.

template <typename K>
bool erase( const K& key );

If an element with the key that compares equivalent to the value key exists, removes it from the container.

This overload only participates in the overload resolution if qualified-id hash_compare_type::is_transparent is valid and denotes a type.

Returns: true if an element is removed; false otherwise.

bool erase( const_accessor& item_accessor );
bool erase( accessor& item_accessor );

Removes an element owned by item_accessor from the container.

Requirements: item_accessor should not be empty.

Returns: true if an element is removed by the current thread; false if it is removed by another thread.