c8bc1bd896
* Corrected the documented make_xxx factory signatures and examples
The Make template sections across the container documentation had
drifted from the implementations, largely through copy-paste:
- map.md, multimap.md and flat-multimap.md all documented
make_flat_map; multiset.md documented make_set; flat-multiset.md
documented make_flat_set; unordered-multimap.md documented
make_unordered_map. Names and examples now match each container.
- Every signature omitted the C++11-required trailing return type
despite the sections being labelled C++11 and above; several also
used a parameter name (TValues) that did not match any template
parameter, and the unordered map headers were missing a comma.
- forward-list.md documented a make_array-style signature with an
explicit element type; the real function deduces the element type as
the common type of the arguments, as documented for make_list.
- The flat_set/flat_multiset template headers were missing the
variadic parameter pack, and their examples passed a braced list to
a variadic function, which does not compile; set.md used TKeyCompare
where the implementation uses TCompare.
- deque.md and the reference container docs were missing code fences.
- Updated the four reference_flat_* function. However these functions
cannot be instantiated at all (the reference containers have no
initializer_list constructor, since one would dangle by design), so
the documented examples have never compiled.
Every remaining documented example verified to compile with clang 22
(C++17) against the current headers.
* Fixed C++17-only syntax in factory examples and flagged the non-compilable ones
Review feedback on the make_xxx documentation examples:
- All the map-family factory examples are labelled C++11 and above but
constructed their pairs with class template argument deduction
(etl::pair{0, 1}), which requires C++17. The pairs in the make_flat_map,
make_flat_multimap, make_map, make_multimap, make_unordered_map,
make_unordered_multimap, make_reference_flat_map and
make_reference_flat_multimap examples now name their template arguments
explicitly. The template deduction guide examples are unchanged, as
those sections are labelled C++17 and above. Verified with clang 22 in
C++14 mode, which, like C++11, has no deduction guides.
- The four make_reference_flat_* examples are now preceded by a warning
callout stating that they do not currently compile: the functions
cannot be instantiated because the reference containers have no
initializer_list constructor. The examples themselves are retained,
rewritten to pass named lvalues rather than temporaries, since the
reference containers store references to external objects and the
temporaries would dangle even if the functions compiled. The defect
is being reported separately.
---------
Co-authored-by: John Wellbelove <jwellbelove@users.noreply.github.com>
9.3 KiB
| title |
|---|
| multimap |
{{< callout type="info">}}
Header: multimap.h
Similar to: std::multimap
{{< /callout >}}
A fixed capacity multimap.
Uses std::less as the default key comparison method.
etl::multimap<typename TKey, typename TMapped, const size_t SIZE, TKeyCompare = etl::less>
Inherits from etl::imap<TKey, TMapped, TKeyCompare>.
etl::imap may be used as a size independent pointer or reference type for any etl::multimap instance.
Template deduction guides
C++17 and above
template <typename... TPairs>
etl::multimap(TPairs...)
Example
etl::multimap data{ etl::pair{0, 1}, etl::pair{2, 3}, etl::pair{4, 5}, etl::pair{6, 7} }
Defines data as an multimap of int/int pairs, of length 4, containing the supplied data.
Make template
C++11 and above
template <typename TKey,
typename TMapped,
typename TKeyCompare = etl::less<TKey>,
typename... TPairs>
constexpr auto make_multimap(TPairs&&... pairs) -> etl::multimap<TKey, TMapped, sizeof...(TPairs), TKeyCompare>
Example
auto data = etl::make_multimap<int, int>(etl::pair<int, int>{0, 1}, etl::pair<int, int>{2, 3},
etl::pair<int, int>{4, 5}, etl::pair<int, int>{6, 7});
Member types
key_type TKey
mapped_type TMapped
value_type etl or std::pair<key_type, mapped_type>
size_type size_t
difference_type ptrdiff_t
reference value_type&
const_reference const value_type&
pointer value_type*
const_pointer const value_type*
iterator Random access iterator
const_iterator Constant random access iterator
reverse_iterator etl or std::reverse_iterator<iterator>
const_reverse_iterator etl or std::reverse_iterator<const_iterator>
Constructor
etl::multimap<Tkey, TMapped, SIZE, TKeyCompare>();
Description
Default constructor.
template <typename TIterator>
etl::multimap<Tkey, TMapped, SIZE, TKeyCompare>(TIterator begin, TIterator end);
Description
Construct from the range [begin, end).
Element access
TMapped& at(key_parameter_t key)
const TMapped& at(key_parameter_t key) const
Description
Returns a reference or const reference to the indexed element.
Asserts an etl::map_out_of_range if the key is not in the table.
If assert or exceptions are not enabled then undefined behaviour occurs.
TMapped& operator[](key_parameter_t key)
const TMapped& operator[](key_parameter_t key) const
Description
Returns a reference or const reference to the indexed element.
If the key does not exist then one is created using the default constructor.
If the multimap is full then asserts an etl::map_full. If asserts or exceptions are not enabled then undefined behaviour occurs.
iterator find(key_parameter_t key);
const_iterator find(key_parameter_t key) const
Description
Searches the container for an element with a key equivalent to key and returns an iterator to it if found, otherwise it returns an iterator to etl::multimap::end().
size_type count(key_parameter_t key) const
Description
Count elements with a specific key.
Searches the container for elements with a key equivalent to key and returns the number of matches
iterator lower_bound(key_parameter_t key);
const_iterator lower_bound(key_parameter_t key) const
Description
Returns an iterator pointing to the first element in the container whose key is not considered to go before key (i.e., either it is equivalent or goes after).
iterator upper_bound(key_parameter_t key);
const_iterator upper_bound(key_parameter_t key) const
Description
Returns an iterator pointing to the first element in the container whose key is considered to go after key.
pair<const_iterator, const_iterator> equal_range(key_parameter_t key) const
pair<iterator, iterator> equal_range(key_parameter_t key)
Description
Returns the bounds of a range that includes all the elements in the container which have a key equivalent to key.
The return type is either std::pair (default) or etl::pair (ETL_NO_STL)
For comparators that define is_transparent.
template <typename K>
iterator find(const K& key)
Description
Searches the container for an element with a key equivalent to key and returns an iterator to it if found, otherwise it returns an iterator to etl::multimap::end().
Since: 20.21.0
C++11 or above.
template <typename K>
const_iterator find(const K& key) const
Description
Searches the container for an element with a key equivalent to key and returns a const iterator to it if found, otherwise it returns a const iterator to etl::multimap::end().
template <typename K>
iterator lower_bound(const K& key)
Description
Returns an iterator pointing to the first element in the container whose key is not considered to go before key (i.e., either it is equivalent or goes after).
Since: 20.21.0
C++11 or above.
template <typename K>
const_iterator lower_bound(const K& key) const
Description
Returns a const iterator pointing to the first element in the container whose key is not considered to go before key (i.e., either it is equivalent or goes after).
Since: 20.21.0
C++11 or above.
template <typename K>
iterator upper_bound(const K& key)
Description
Returns an iterator pointing to the first element in the container whose key is considered to go after key.
Since: 20.21.0
C++11 or above.
template <typename K>
const_iterator upper_bound(const K& key) const
Description
Returns a const iterator pointing to the first element in the container whose key is considered to go after key.
Since: 20.21.0
C++11 or above.
template <typename K>
pair<iterator, iterator> equal_range(const K& key)
Description
Returns the bounds of a range that includes all the elements in the container which have a key equivalent to key.
The return type is either std::pair (default) or etl::pair (ETL_NO_STL)
Since: 20.21.0
C++11 or above.
template <typename K>
pair<const_iterator, const_iterator> equal_range(const K& key) const
Description
Returns the bounds of a range that includes all the elements in the container which have a key equivalent to key.
The return type is either std::pair (default) or etl::pair (ETL_NO_STL)
bool contains(key_value_parameter_t key) const
Description
Check if the container contains the key.
Since: 20.21.0
template <typename K>
bool contains(const K& k) const
Description
Check if the container contains the key.
Since: 20.21.0
C++11 or above.
For comparators that define is_transparent.
Iterators
iterator begin()
const_iterator begin() const
const_iterator cbegin() const
Description
Returns an iterator to the beginning of the multimap.
iterator end()
const_iterator end() const
const_iterator cend() const
Description
Returns an iterator to the end of the multimap.
iterator rbegin()
const_iterator rbegin() const
const_iterator crbegin() const
Description
Returns a reverse iterator to the beginning of the multimap.
iterator rend()
const_iterator rend() const
const_iterator crend() const
Description
Returns a reverse iterator to the end of the multimap.
Capacity
bool empty() const
Description
Returns true if the size of the multimap is zero, otherwise false.
bool full() const
Description
Returns true if the size of the multimap is SIZE, otherwise false.
size_t size() const
Description
Returns the size of the multimap.
size_t max_size() const
Description
Returns the maximum possible size of the multimap.
size_t available() const
Description
Returns the remaining available capacity in the multimap.
Modifiers
template <typename TIterator>
void insert(TIterator begin, TIterator end)
Description
Before: 20.20.0
template <typename TIterator>
iterator insert(TIterator begin, TIterator end)
Description
Since: 20.20.0
iterator insert(mapped_parameter_t value)
Description
Inserts values in to the multimap.
If the multimap is full then asserts an etl::map_full error. If asserts or exceptions are not enabled then undefined behaviour occurs.
template <typename TIterator>
iterator erase(TIterator begin, TIterator end)
Description
iterator erase(TIterator element)
Description
Erases values in the multimap.
Iterator are not checked for validity.
size_t erase(const key_type& key)
Description
20.21.0
template <typename K>
size_t erase(K&& key)
Description
void clear()
Description
Clears the multimap to a size of zero.
Non-member functions
operator ==
Description
true if the contents of the maps are equal, otherwise false.
operator !=
Description
true if the contents of the maps are not equal, otherwise false.