void push_back(const value_type& _Val) { // insert element at end if (_Inside(_STD addressof(_Val))) { // push back an element size_type _Idx = _STD addressof(_Val) - _Unfancy(this->_Myfirst()); if (this->_Mylast() == this->_Myend()) _Reserve(1); _Orphan_range(...
the size of astd::vectorcan change during runtime. It achieves this dynamic resizing through memory allocations and deallocations. When you insert an element into a vector that’s already at its capacity, the vector will allocate a new, larger block of memory, move the existing elements to t...
我认为，如果您只是对索引进行排序，然后从向量中从最高到最低删除这些元素，那么它可能会更有效率。
STD::vector<bool, Allocator> &t,constunsignedint/* file_version */){// retrieve number of elementsunsignedintcount; ar >> BOOST_SERIALIZATION_NVP(count); t.clear();while(count-- >0){booli; ar >> boost::serialization::make_nvp("item", i); t.push_back(i); } } 开发者ID:Albermg7...
你遇到的第一个问题是空间。由于您只需要1-10之间的数字，因此int8_t会更好地为您服务。
#include <vector>#include <iostream>usingfoo = std::vector<double>;intmain() { std::vector<foo> Vfoo(3); Vfoo[0].resize(20); Vfoo[1].resize(1);for(unsignedi = 0; i<20; ++i) Vfoo[2].push_back(3.14*i) ; std::cout <<"Vfoo[0]:\n"; std::cout <<"\tsizeof = "<...
small_vector基本兼容std::vector的接口。 small_vector<int,2> vec; vec.push_back(0);// Stored in-place on stackvec.push_back(1);// Still on the stackvec.push_back(2);// Switches to heap buffer. small_vector<int,2> vec指定可以内联在对象中2个数据: ...
The first test that is performed is to fill the data structures by adding elements to the back of the container (usingpush_back). Two variations of vector are used,vector_prebeing a std::vector using vector::reserve at the beginning, resulting in only one allocation of memory. ...
It first populates the vector scores with integers from 1 to 5 using the push_back() function. Output: 1 2 3 Output of begin() and end(): 1 2 3 4 5 Output of rbegin() and rend(): 5 4 3 2 1 Accessing C++ Vector Elements by using Access Functions Vector elements can...
typedef std::vector<foo > vectorFoo; typedef std::vector<bar > vectorBar; union vectorAll { vectorFoo foo_; vectorBar bar_; }; static vectorAll myVectorAll; ... foo myFoo; myVectorAll.foo _.push_back(myF oo); myVectorAll.foo _.clear(); ....