Friend functions for C + + template classes

1 #pragmaOnce2#include <iostream>3 4Template <classT>5 classStack6 {7Template <classTy>8Friend std::ostream&operator<< (std::ostream& OS,Conststack<ty>&s);9  Public:Ten     ExplicitStack<t> (intmaxSize); OneStack<t> (Conststack<t>&s); AStack<t> (stack<t>&&) =Delete; -stack<t>&operator=(Conststack&s); -stack<t>&operator= (stack<t>&&) =Delete; the~stack<t>(); -  -     voidpush (T e); -     BOOLPop (t&e); +     BOOLGetTop (t& e)Const; -  +     BOOLIsEmpty ()Const; A     intGetnumelems ()Const; at  - Private: -t*Elems; -     inttop; -     intmaxSize; -     voidoverflowprocess (); in }; -  toTemplate <classT> +std::ostream&operator<< (std::ostream& OS,Conststack<t>&s) - { the      for(inti =0; I <= s.top; i++) *     { $Std::cout << S.elems[i] <<" ";Panax Notoginseng     } -     returnos; the } +  ATemplate <classT> theStack<t>::stack (intMaxsize_): Top (-1), MaxSize (maxsize_) + { -      This->elems =Newt[ This-MaxSize]; $ } $  -Template <classT> -Stack<t>::stack (Conststack<t>&s) the { -      This->top =S.top;Wuyi      This->maxsize =s.maxsize; the      This->elems =Newt[ This-MaxSize]; -memcpy_s ( This->elems,sizeof(T) * maxSize, S.elems,sizeof(T) *maxSize); Wu } -  AboutTemplate <classT> $stack<t>& Stack<t>::operator=(Conststack&s) - { -     if( This= = &s)return* This; -     if( This->elems! = nullptr)Delete[] elems; A      This->top =S.top; +      This->maxsize =s.maxsize; the      This->elems =NewT[maxsize]; -memcpy_s ( This->elems,sizeof(T) * maxSize, S.elems,sizeof(T) *maxSize); $     return* This; the } the  theTemplate <classT> thestack<t>::~Stack () - { in     if( This->elems! =nullptr) the         Delete[] elems; the } About  theTemplate <classT> the voidStack<t>::p ush (T e) the { +     if( This->top = = MaxSize-1) -     { the overflowprocess ();Bayi     } the      This->elems[++top] =e; the } -  -Template <classT> the BOOLStack<t>::p op (t&e) the { the     if(!isEmpty ()) the     { -E = This->elems[top--]; the         return true; the     } the     return false;94 } the  theTemplate <classT> the BOOLStack<t>::gettop (t& e)Const98 { About     if(!isEmpty ()) -     {101E =Elems[top];102         return true;103     }104     return false; the }106 107Template <classT>108 BOOLStack<t>::isempty ()Const109 { the     returntop = =-1?true:false;111 } the 113Template <classT> the intStack<t>::getnumelems ()Const the { the     returnTop +1;117 }118 119Template <classT> - voidStack<t>:: overflowprocess ()121 {122t* New_elems =NewT[maxsize + maxSize/3];123memcpy_s (New_elems,sizeof(T) * maxSize, This->elems,sizeof(T) *maxSize);124     Delete[] elems; the      This->elems =New_elems;126}

The code is long; it's too lazy to cut .... A stack class with basic functions, which can be used directly

It is used in: template friend function is defined outside the class to be added Template<class ty> to differentiate

Therefore: template friend function: In-class definition does not need template<class ty>/////actually this is not sure, next time try to know

Intra-class declaration, out-of-class definition: Requires Tempalte<class ty>

Friend functions for C + + template classes