cppreference.com 创建账户 页面 讨论 变换 查看 编辑 历史 std::vector C++ 容器库 std::vector 在标头<vector>定义 template< classT, classAllocator=std::allocator<T> >classvector; (1) namespace { template<classT> usingvector=std::vector<T,std::pmr::polymorphic_allocator<T>>; ...
bool c = false); constexpr void reserve(size_type n); constexpr void shrink_to_fit(); // 元素访问 constexpr reference operator[](size_type n); constexpr const_reference operator[](size_type n) const; constexpr const_reference at(size_type n) const; constexpr reference at(size_type ...
__cpp_lib_ranges_reserve_hint202502L(C++26)ranges::approximately_sized_range,ranges::reserve_hint, and changes tostd::vector Example Run this code #include <iostream>#include <vector>intmain(){// Create a vector containing integersstd::vector<int>v={8,4,5,9};// Add two more integers ...
The number of elements in ainplace_vectormay vary dynamically up to a fixed capacity because elements are stored within the object itself similarly tostd::array. However, objects are initialized as they are inserted intoinplace_vectorunlike C arrays orstd::array, which must construct all elements...
安插和删除元素,会使“作用点”之后的各元素的reference、pointers、iterators失效,如果安插操作导致内存重新分配,该容器的所有reference、pointers、iterators都会失效。 4、代码示例 //cont/vector1.cpp#include<iostream>#include<vector>#include<string>#include<algorithm>usingnamespacestd;intmain() ...
(2, 3.14, 'c') std::cout << size(t) << std::endl; // => 3 std::cout << last(t) << ", " << last2(t) << std::endl; // => c, c return 0; } // filename: ch1-tuple-constexpr-last.cpp // compile this> g++ ch1-tuple-constexpr-last.cpp -o ch1-tuple-const...
voidswap(std::vector<T, Alloc>&lhs, std::vector<T, Alloc>&rhs); (until C++17) template<classT,classAlloc> voidswap(std::vector<T, Alloc>&lhs, std::vector<T, Alloc>&rhs) noexcept(/* see below */); (since C++17) (constexpr since C++20) ...
(vector<T, Allocator>&c,constU&value);template<classT,classAllocator,classPredicate>voiderase_if(vector<T, Allocator>&c, Predicate pred);template<classAllocator>classvector<bool,Allocator>;// 散列支持template<classT>structhash;template<classAllocator>structhash<vector<bool, Allocator>>;namespacepmr...
reference front():返回首元素的引用 reference back():返回尾元素的引用 iterator begin():返回向量头指针,指向第一个元素 iterator end():返回向量尾指针,指向向量最后一个元素的下一个位置 reverse_iterator rbegin():反向迭代器,指向最后一个元素 reverse_iterator rend():反向迭代器,指向第一个元素之前的位置...
我阅读了std::vector的扣除指南从使用cppreference. 示例: #include <vector> int main() { std::vector<int> v = {1, 2, 3, 4}; std::vector x{v.begin(), v.end()}; // uses explicit deduction guide } 所以,我对此有一些疑问: