C++模板简单学习

到后面学习开始变懒了 从代码就看出来了

#ifndef ARRAY_H#define  ARRAY_H#include <iostream>template <class T,int size=10>class A{T o[size];public:int length()const { return size; }T &operator[](int i);};template < class T,int size>T&A<T, size>::operator[](int i){if (i >= 0 && i < size)return o[i];}class N{private:float f;public:operator float()const{return f;}N &operator=(const N &c){f = c.f;return *this;}friend std::ostream &operator<< (std::ostream &os, const N&n){return os << n.f;}N(float ff=0.0f) :f(ff){}};template<class T,int size=20>class H{A <T,size> *np;public:H() :np(NULL){}T &operator[](int i){if (!np){np = new A<T, size>;}return np->operator[](i);}int length()const { return size; }~H(){delete np;}};#endif