A type that represents the allocator class for the vector object. 複製 typedef Allocator allocator_type; Remarks allocator_type is a synonym for the template parameter Allocator. Example See the example for get_allocator for an example that uses allocator_type. Requirements Header: <vector> ...
If a reallocation happens, it is performed usingAllocator::allocate(), which may throw exceptions (for the defaultallocator,bad_allocis thrown if the allocation request does not succeed). Example // vector::push_back#include<iostream>#include<vector>intmain(){ std::vector<int> myvector;intmyi...
template < class T, class Alloc = allocator<T> > class vector; // generic template 当你写个程序比如下面这个 #include <bits/stdc++.h>intmain(){intn; std::cin>>n; std::vector<int>v;for(inti =0; i < n; i++) std::cin >>v[i];for(inti =0; i < n; i++) std::cout <...
问具有私有构造函数的对象的vector::emplace_backEN您可以使用友谊转移语义来避免使用专门的vector分配器。...
classAllocator=std::allocator<T> >classvector; (1) namespace { template<classT> usingvector=std::vector<T,std::pmr::polymorphic_allocator<T>>; } (2) (since C++17) 1)std::vectoris a sequence container that encapsulates dynamic size arrays. ...
-> std::vector<AdItem, std::allocator<AdItem> >::vector --> std::vector<AdItem, std::allocator<AdItem> >::_M_fill_initialize ---> std::__uninitialized_fill_n_a<AdItem*, unsigned long, AdItem, AdItem> ---> std::uninitialized_fill_n<AdItem*, unsigned long, AdItem> -...
Writing and using your own allocator class is an advanced C++ feature.ExampleC++ Copy // vector_get_allocator.cpp // compile with: /EHsc #include <vector> int main() { using namespace std; // The following lines declare objects that use the default allocator. vector<int> v1; vector<...
Example 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 // vector::get_allocator#include <iostream>#include <vector>intmain () { std::vector<int> myvector;int* p;unsignedinti;// allocate an array with space for 5 elements using vector's allocator...
vector (vector&& x); vector (vector&& x, const allocator_type& alloc); 参数(Parameters) x - 相同类型的另一个向量容器。 返回值 构造函数永远不会返回值。 异常(Exceptions) 该成员函数从不抛出异常。 时间复杂 线性即O(n) 例子(Example) 以下示例显示了move构造函数std :: vector :: vector()的用...
<scoped_allocator> <set> <shared_mutex> <sstream> <stack> <stdexcept> <streambuf> <string> <string_view> <strstream> <system_error> <thread> <tuple> <type_traits> <typeindex> <typeinfo> <unordered_map> <unordered_set> <utility