Lookup

All methods in this section can be executed concurrently with each other, concurrently-safe modifiers and while traversing the container.

count

size_type count( const key_type& key );

Returns: the number of elements equivalent to key.

---

template <typename K>
size_type count( const K& key );

Returns: the number of elements that are equivalent to key.

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

find

iterator find( const key_type& key );

const_iterator find( const key_type& key ) const;

Returns: an iterator to the element equivalent to key or end() if no such element exists.

If there are multiple elements equivalent to key, it is unspecified which element should be found.

---

template <typename K>
iterator find( const K& key );

template <typename K>
const_iterator find( const K& key ) const;

Returns: an iterator to the element that is equivalent to key, or end() if no such element exists.

If there are multiple elements that are equivalent to key, it is unspecified which element should be found.

These overloads only participate in overload resolution if qualified-id key_compare::is_transparent is valid and denotes a type.

contains

bool contains( const key_type& key ) const;

Returns: true if at least one element equivalent to key exists in the container; false, otherwise.

---

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

Returns: true if at least one element that is equivalent to key exists in the container; false, otherwise.

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

lower_bound

iterator lower_bound( const key_type& key );

const_iterator lower_bound( const key_type& key ) const;

Returns: an iterator to the first element in the container that is not less than key.

---

template <typename K>
iterator lower_bound( const K& key )

template <typename K>
const_iterator lower_bound( const K& key ) const

Returns: an iterator to the first element in the container that is not less than key.

These overloads only participate in overload resolution if qualified-id key_compare::is_transparent is valid and denotes a type.

upper_bound

iterator upper_bound( const key_type& key );

const_iterator upper_bound( const key_type& key ) const;

Returns: an iterator to the first element in the container that compares greater than key.

---

template <typename K>
iterator upper_bound( const K& key );

template <typename K>
const_iterator upper_bound( const K& key ) const;

Returns: an iterator to the first element in the container that compares greater than key.

These overloads participate in overload resolution only if qualified-id key_compare::is_transparent is valid and denotes a type.

equal_range

std::pair<iterator, iterator> equal_range( const key_type& key );

std::pair<const_iterator, const_iterator> equal_range( const key_type& key ) const;

Returns: if at least one element equivalent to key exists, a pair of iterators {f, l}, where f is an iterator to the first element equivalent to key, l is an iterator to the element that follows the last element equivalent to key. Otherwise, {end(), end()}.

---

template <typename K>
std::pair<iterator, iterator> equal_range( const K& key )

template <typename K>
std::pair<const_iterator, const_iterator> equal_range( const K& key )

Returns: if at least one element that is equivalent to key exists, a pair of iterators {f, l},

where f is an iterator to the first element that is equivalent to key, l is an iterator to the element that follows the last element that is equivalent to key. Otherwise, {end(), end()}.

These overloads participate in overload resolution only if qualified-id key_compare::is_transparent is valid and denotes a type.