STL Containers

作者: 龙遁流 | 来源:发表于2017-02-04 15:16 被阅读0次

容器的共性

1，所有容器中元素都是值而不是引用，元素插入容器的时候容器拷贝或移动元素，即元素必须能够被拷贝或移动。但也可以存储元素的指针来避免拷贝。

2，容器中的元素都是有特定顺序的，不管是不是有序或无序容器，只要没有进行插入和删除操作，利用迭代器遍历多次得到的顺序是一样的。

3，STL本身一般不抛出异常

Req表示容器通用的操作

移动迭代器

std::vector<std::string> c(std::make_move_iterator(l.begin()),std::make_move_iterator(l.end()));

获取数组迭代器

int arr;

std::begin(arr)，std::end(arr)

流迭代器

std::deque<int> c((std::istream_iterator<int>(std::cin)),(std::istream_iterator<int>()));

All containers except vectors and deques guarantee that iterators and references to elements remain valid if other elements are deleted. For vectors, only the elements before the point of erase remain valid.

If you remove all elements by using clear(), for vectors, deques, and strings any past-the-end iterator returned by end() or cend() may become invalid.

If you insert elements, only lists, forward lists, and associative containers guarantee that iterators and references to elements remain valid. For vectors, this guarantee is given if insertions don’t exceed the capacity. For unordered containers, that guarantee is given to references in general but to iterators only when no rehashing happens, which is guaranteed as long as with insertions the number of resulting elements is less than the bucket count times the maximum load factor.

容器通用类型

Arrays

类array<>定义在<array>，为普通的静态数组提供容器的操作，未提供参数为初始值列表的构造函数和赋值操作，但提供了移动操作

std::array<int, 5> coll = { 42, 377, 611, 21, 44 };

array的元素是连续存储的

std::array<char, 41>a; // create static array of 41 chars

strcpy(a.data(),"hello, world"); // copy a C-string into the array

printf("%s\n", a.data()); // print contents of the array as C-string

array提供tuple接口

typedef std::array<std::string, 5> FiveStrings;

FiveStrings a = { "hello", "nico", "how", "are", "you" };

std::tuple_size<FiveStrings>::value // yields 5

std::tuple_element<1,FiveStrings>::type // yields std::string

std::get<1>(a) // yields std::string("nico")

// negate all elements

transform(a.begin(),a.end(), a.begin(),negate<int>()); // operation

Vectors