vector C++实现

闲来蛋疼，练练手。

参考标准库的vector实现。与STL源码相比大同小异，主要功能都以实现。

#include<iostream>#include<algorithm>#include<memory>using namespace std;template<class T>class Vector{public:typedef T value_Type;typedef value_Type* Pointer;typedef value_Type* iterator;typedef value_Type& reference;typedef size_t size_type;typedef ptrdiff_t difference_type;protected:iterator start;iterator finish;iterator end_of_storage;void insert_aux(iterator position,const T& x);void fill_initialize(size_type n, const T& value){start = allocate_and_fill(n,value);finish = start + n;end_of_storage = finish;}iterator allocate_and_fill(const size_type n, const T& value){iterator result = new value_Type[n];uninitialized_fill_n(result,n,value);return result;}iterator uninitialized_fill_n(iterator first,size_t n ,const T& x){iterator tmp_start = first;while(n--){*first++ = x;}return tmp_start;}public:iterator begin(){return start;}iterator end(){return finish;}size_type size(){return size_type(end()-begin());}bool empty()const{return begin() == end();}reference operator[](size_type n){return *(begin()+n);}Vector():start(0),finish(0),end_of_storage(0){}Vector(size_type n, const T& value){fill_initialize(n,value);}Vector(int n, const T& value){fill_initialize(n,value);}Vector(long n, const T& value){fill_initialize(n,value);}explicit Vector(size_type n){fill_initialize(n,T());}~Vector(){destory(start,finish);deallocate(start);}void deallocate(iterator iter){delete []iter;}void destory(iterator iter){iter->~T();}void destory(iterator start, iterator finish){int i=0;while ((start+i) != finish){(start+i)->~T();i++;}}reference front(){return *begin();}reference back(){return *(end()-1);}void push_back(const T& x){if(finish!=end_of_storage)*finish = x;else{insert(end(),1,x);}++finish;}void pop_back(){--finish;destory(finish);}iterator erase(iterator position){if(position+1 != end())copy(position+1,finish,position);--finish;destory(finish);return position;}iterator erase(iterator first,iterator last){iterator tmp = copy(last,finish,first);destory(tmp,finish);finish = finish - (last-first);return first;}void resize(size_type new_size,const T& x){if(new_size< size())erase(begin()+new_size,end());else insert(end(),new_size-size(),x);}void resize(size_type new_size){resize(new_szie,T());}void clear(){erase(begin(),end());}void insert(iterator position,size_type n,const T& x){if(n!=0){//备用空间大于新增元素个数if(size_type(end_of_storage-finish)>=n){T x_copy;const size_type elems_after = finish -position;iterator old_finish = finish;if(elems_after > n){uninitialized_copy(finish-n,finish,finish);finish += n;copy_backward(position,old_finish-n,old_finish);fill(position,position+n,x_copy);}else{uninitialized_fill_n(finish,n-elems_after,x_copy);finish += n - elems_after;uninitialized_copy(position,old_finish,finish);finish += elems_after;fill(position,old_finish,x_copy);}}else{ //备用空间不足const size_type old_size = size();const size_type len = old_size + max(old_size,n);iterator new_start = reallocate(old_size+2*(max(old_size,n)));//新增元素个数为不足空间个数的2倍iterator new_finish = new_start;try{// 将vector插入点之前的元素复制到新空间new_finish = uninitialized_copy(start,position,new_start);new_finish = uninitialized_fill_n_my(new_finish,n,x);new_finish = uninitialized_copy(position,finish,new_finish);}//#ifdef _STL_USE_EXCEPTIONScatch(...){//若发生异常，回滚保持原有向量destory(new_start,new_finish);deallocate(new_start);throw;}//#endifdestory(start,finish);deallocate(start);start = new_start;finish = new_finish;end_of_storage = new_start + len;}}}iterator uninitialized_copy(iterator first,iterator last,iterator res){while(first!=last){*(res++) = *(first++); }return res;}iterator copy_backward(iterator first,iterator last,iterator res){while(last!=first){*(--res) = *(--last);}return res;}iterator reallocate(const size_t len){iterator iter;iter = new T[len];return iter;}iterator uninitialized_fill_n_my(iterator start,size_t n, const T& x){while(n--){*(start++) = x;}return start;}iterator find(iterator first,iterator last,const T& value){while(first!=last){if(*first == value)return first;++first;}return first;}};void test1(){//测试各种类型数据存储Vector<int> Vint(10,2);for(Vector<int>::iterator iter =Vint.begin();iter!= Vint.end();++iter)cout<<*iter<<" ";cout<<endl;Vector<float>Vflt(10,2.1);for(Vector<float>::iterator iter =Vflt.begin();iter!= Vflt.end();++iter)cout<<*iter<<" ";cout<<endl;Vector<double>Vdoub(10,2.13);for(Vector<double>::iterator iter =Vdoub.begin();iter!= Vdoub.end();++iter)cout<<*iter<<" ";cout<<endl;class TT{int tmp;public:TT(int a=0):tmp(a){}operator int(){return tmp;}};Vector<TT>Vtt(10,TT(3));for(Vector<TT>::iterator iter =Vtt.begin();iter!= Vtt.end();++iter)cout<<*iter<<" ";cout<<endl;}void test2(){//测试插入Vector<int> Vint(10,2);Vector<int>::iterator iter =Vint.end();Vint.insert(----iter,2,3);Vint.push_back(4);for(iter=Vint.begin();iter!= Vint.end();++iter)cout<<*iter<<" ";cout<<endl;}void test3(){//测试删除Vector<int> Vint(10,2);Vector<int>::iterator iter =Vint.end();Vint.insert(----iter,2,3);Vint.push_back(4);for(iter=Vint.begin();iter!= Vint.end();++iter)cout<<*iter<<" ";cout<<endl;Vector<int>::iterator iter1 = Vint.find(Vint.begin(),Vint.end(),3);Vint.erase(iter1,Vint.end());for(iter=Vint.begin();iter!= Vint.end();++iter)cout<<*iter<<" ";cout<<endl;iter = Vint.end();Vint.erase(--iter);for(iter=Vint.begin();iter!= Vint.end();++iter)cout<<*iter<<" ";cout<<endl;}int main(){cout<<"----------test1---------"<<endl;test1();cout<<"----------test2---------"<<endl;test2();cout<<"----------test3---------"<<endl;test3();}