Difference between revisions of "cpp/container/set"
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{{dsc inc | cpp/container/dsc reverse_iterator | set}} | {{dsc inc | cpp/container/dsc reverse_iterator | set}} | ||
{{dsc inc | cpp/container/dsc const_reverse_iterator | set}} | {{dsc inc | cpp/container/dsc const_reverse_iterator | set}} | ||
+ | {{dsc inc | cpp/container/dsc node_type | set}} | ||
+ | {{dsc inc | cpp/container/dsc insert_return_type | set}} | ||
{{dsc end}} | {{dsc end}} | ||
Revision as of 13:06, 19 July 2016
Defined in header <set>
|
||
(1) | ||
template< class Key, |
(until C++17) | |
template< class Key, |
(since C++17) | |
namespace pmr { template <class Key, class Compare = std::default_order_t<Key>> |
(2) | (since C++17) |
std::set
is an associative container that contains a sorted set of unique objects of type Key
. Sorting is done using the key comparison function Template:concept. Search, removal, and insertion operations have logarithmic complexity. Sets are usually implemented as red-black trees.
Everywhere the standard library uses the Template:concept concept, uniqueness is determined by using the equivalence relation. In imprecise terms, two objects a
and b
are considered equivalent (not unique) if neither compares less than the other: !comp(a, b) && !comp(b, a)
.
std::set
meets the requirements of Template:concept, Template:concept, Template:concept and Template:concept.
Contents |
Member types
Member type | Definition | ||||
key_type
|
Key
| ||||
value_type
|
Key
| ||||
size_type
|
Unsigned integer type (usually std::size_t) | ||||
difference_type
|
Signed integer type (usually std::ptrdiff_t) | ||||
key_compare
|
Compare
| ||||
value_compare
|
Compare
| ||||
allocator_type
|
Allocator
| ||||
reference
|
value_type& | ||||
const_reference
|
const value_type& | ||||
pointer
|
| ||||
const_pointer
|
| ||||
iterator
|
Constant LegacyBidirectionalIterator to value_type
| ||||
const_iterator
|
LegacyBidirectionalIterator to const value_type | ||||
reverse_iterator
|
std::reverse_iterator<iterator> | ||||
const_reverse_iterator
|
std::reverse_iterator<const_iterator> | ||||
node_type (since C++17)
|
a specialization of node handle representing a container node | ||||
insert_return_type (since C++17)
|
type describing the result of inserting a node_type , a specialization oftemplate<class Iter, class NodeType> |
Member functions
constructs the set (public member function) | |
destructs the set (public member function) | |
assigns values to the container (public member function) | |
returns the associated allocator (public member function) | |
Iterators | |
(C++11) |
returns an iterator to the beginning (public member function) |
(C++11) |
returns an iterator to the end (public member function) |
(C++11) |
returns a reverse iterator to the beginning (public member function) |
(C++11) |
returns a reverse iterator to the end (public member function) |
Capacity | |
checks whether the container is empty (public member function) | |
returns the number of elements (public member function) | |
returns the maximum possible number of elements (public member function) | |
Modifiers | |
clears the contents (public member function) | |
inserts elements or nodes(since C++17) (public member function) | |
(C++11) |
constructs element in-place (public member function) |
(C++11) |
constructs elements in-place using a hint (public member function) |
erases elements (public member function) | |
swaps the contents (public member function) | |
Lookup | |
returns the number of elements matching specific key (public member function) | |
finds element with specific key (public member function) | |
returns range of elements matching a specific key (public member function) | |
returns an iterator to the first element not less than the given key (public member function) | |
returns an iterator to the first element greater than the given key (public member function) | |
Observers | |
returns the function that compares keys (public member function) | |
returns the function that compares keys in objects of type value_type (public member function) |
Non-member functions
(removed in C++20)(removed in C++20)(removed in C++20)(removed in C++20)(removed in C++20)(C++20) |
lexicographically compares the values of two set s (function template) |
specializes the std::swap algorithm (function template) |
Notes
The member types iterator
and const_iterator
may be aliases to the same type. This means defining a pair of function overloads using the two types as parameter types may violate the One Definition Rule. Since iterator
is convertible to const_iterator
, a single function with a const_iterator
as parameter type will work instead.