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学c++同学必会的一项技能必须懂得STL,STL真的非常的强大,因此自己想实现一个自己的STL库,因此在读了《STL源码剖析》之后,开始了编写自己的库道路,如果你有兴趣,欢迎和我一起研究,完整的代码和测试案例在我的Github:
<memory>
中。typedef T value_type; typedef value_type* iterator; typedef const value_type* const_iterator; typedef value_type& reference; typedef value_type* pointer; typedef size_t size_type; typedef ptrdiff_t difference_type; //表示两个迭代器之间的距离 ,c++内置定义 typedef int ptrdiff_t;
iterator _start; //数组的首元素 iterator _end; //目前使用空间的尾 iterator _end_of_storage; //目前可用空间的尾
myVector() :_start(0), _end(0), _end_of_storage(0){}//默认构造函数 myVector(size_type n, const T& value); myVector(size_type n); myVector(iterator first, iterator last); myVector(const myVector& v); //复制构造函数 myVector& operator=(const myVector& rhs); //赋值操作符函数
iterator begin() { return _start; } iterator end() { return _end; } const_iterator cbegin() const { return _start; } //常量迭代器 const_iterator cend() const { return _end; } size_type size() { return size_type(end() - begin()); } //注意转换成size_t类型 size_type capacity() { return size_type(_end_of_storage - begin()); } bool empty() { return begin() == end(); } void swap(myVector &other); reference front() { return *begin(); } reference back() { return *(end() - 1); } reference operator[] (size_type n) { return *(begin() + n); } //重载[],这样可以用a[n]进行访问元素 //删除数组中的元素,并且释放内存 void insert_aux(iterator positon, const T& x); //一个插入辅助的函数,在向量为满的时候用到 void push_back(const T& value); void pop_back(); void insert(iterator position, size_type n, const T& x); iterator erase(iterator position); iterator erase(iterator first, iterator last); //删除[first,last)的元素 void clear() { erase(begin(), end()); }
**下面是自己的测试结果,测试的样本并不多,因此肯定有Bug,如果有兴趣,欢迎指出。**
#include "myVector.h"#include#include using namespace std;int main(){ myVector v; cout << "测试默认构造函数" << endl; cout << v.size() << " " << v.capacity() << endl; cout << "测试构造函数,构造10个1元素" << endl; myVector v1(10, 1); for (int i = 0; i < v1.size(); i++) cout << v1[i] <<" "; //操作符重载[]成功 cout << endl; cout << "得到头和尾的值" << endl; cout < <<" "< << endl; //测试函数 cout << endl; cout << "测试复制构造函数" << endl; myVector vcopy(v1); for (int i = 0; i < vcopy.size(); i++) cout << vcopy[i] <<" "; cout << endl; cout << "测试赋值操作符" << endl; myVector vv; vv = v1; for (int i = 0; i < vv.size(); i++) cout << vv[i] << " "; cout << endl; cout << "测试构造函数,构造n个0元素" << endl; myVector v2(10); for (int i = 0; i < v2.size(); i++) cout << v2[i] << " "; cout << "测试是否为空" << endl; cout < << v2.empty() << endl; cout << "测试push_back()" << endl; v2.push_back(3); cout << v2.size() << " " << v2.capacity() << " " << v2[1] << endl; cout << "测试pop_back()" << endl; v2.pop_back(); cout << v2.size() << " " << v2.capacity() << " " << v2[10] << endl; cout << "测试erase(fisrt,last)" << endl; for (int i = 0; i < v2.size(); i++) { v2[i] += i; cout << v2[i] << " "; } cout << endl; v2.erase(v2.begin(), v2.begin() + 2); //从开始,删除两个元素 for (int i = 0; i < v2.size(); i++) cout << v2[i] << " "; cout << endl; cout << "测试erase(positon)" << endl; v2.erase(v2.begin() + 2); for (int i = 0; i < v2.size(); i++) cout << v2[i] << " "; cout << endl; //测试重要的函数insert() cout << "测试insert(iterator positon, size_type n, const T& x)" << endl; myVector vec(5, "test"); for (int i = 0; i < vec.size(); i++) cout << vec[i] << " " ; cout << endl; vec.insert(vec.begin() + 2, 7, "program"); //加入7个相同字符 for (int i = 0; i < vec.size(); i++) cout << vec[i] << " "; cout << endl; cout << vec.size() << " " << vec.capacity() << endl; cout << "测试迭代器" << endl; myVector str(10, "test"); auto it = str.begin(); //auto位c++11关键字,判断类型 for (; it != str.end(); ++it) cout << *it << " "; cout << endl; cout << "使矩阵给容器赋初值" << endl; int a[] = { 1,2,3,4,5,6,7,8,9 }; myVector v4(a, a + sizeof(a)/sizeof(a[0])); for (int i = 0; i < v4.size(); i++) cout << v4[i] << " "; cout << endl;}
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