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📜  C++ STL-Set

📅  最后修改于: 2020-10-20 06:16:00             🧑  作者: Mango

C++ STL Set

Set介绍

set是C++ STL(标准模板库)的一部分。集合是存储排序键的关联容器，其中每个键都是唯一的，可以插入或删除但不能更改。

句法

template < class T,                             // set::key_type/value_type
           class Compare = less,        // set::key_compare/value_compare
           class Alloc = allocator         // set::allocator_type
           > class set;

参数

T：存储在容器set中的元素类型。

比较：比较类，它接受两个相同类型的布尔变量，并返回一个值。此参数是可选的，二进制谓词较少，是默认值。

Alloc：用于定义存储分配模型的分配器对象的类型。

会员职能

以下是set的所有成员函数的列表：

构造函数/析构函数

Functions Description
(constructor) Construct set
(destructor) Set destructor
operator= Copy elements of the set to another set.

迭代器

Functions Description
Begin Returns an iterator pointing to the first element in the set.
cbegin Returns a const iterator pointing to the first element in the set.
End Returns an iterator pointing to the past-end.
Cend Returns a constant iterator pointing to the past-end.
rbegin Returns a reverse iterator pointing to the end.
Rend Returns a reverse iterator pointing to the beginning.
crbegin Returns a constant reverse iterator pointing to the end.
Crend Returns a constant reverse iterator pointing to the beginning.

容量

Functions Description
empty Returns true if set is empty.
Size Returns the number of elements in the set.
max_size Returns the maximum size of the set.

修饰符

Functions Description
insert Insert element in the set.
Erase Erase elements from the set.
Swap Exchange the content of the set.
Clear Delete all the elements of the set.
emplace Construct and insert the new elements into the set.
emplace_hint Construct and insert new elements into the set by hint.

观察者

Functions Description
key_comp Return a copy of key comparison object.
value_comp Return a copy of value comparison object.

运作方式

Functions Description
Find Search for an element with given key.
count Gets the number of elements matching with given key.
lower_bound Returns an iterator to lower bound.
upper_bound Returns an iterator to upper bound.
equal_range Returns the range of elements matches with given key.

分配者

Functions Description
get_allocator Returns an allocator object that is used to construct the set.

非成员重载函数

Functions Description
operator== Checks whether the two sets are equal or not.
operator!= Checks whether the two sets are equal or not.
operator< Checks whether the first set is less than other or not.
operator<= Checks whether the first set is less than or equal to other or not.
operator> Checks whether the first set is greater than other or not.
operator>= Checks whether the first set is greater than equal to other or not.
swap() Exchanges the element of two sets.