template templatetypename T , int N

1.h
#ifndef _1_H_
#define _1_H_

template <typename T,int N>
class ARRAY
{
	int length;
	T array[N];
	public:
		ARRAY();
		bool setvalue(int index,T value);
		bool getvalue(int index,T& value);
		int getlen();
		T& operator[](int index);
		T operator[](int index)const;
};

template <typename T,int N>
ARRAY<T,N>::ARRAY()
{
	length=N;
}

template <typename T,int N>
bool ARRAY<T,N>::setvalue(int index,T value)
{	
	bool ret = 0;
	if( (index<N)&&(index>0) )
	{
		array[index] = value;
		ret = 1;
	}
	return ret;
}

template <typename T,int N>
bool ARRAY<T,N>::getvalue(int index,T& value)
{
	bool ret = 0;
	if( (index<N)&&(index>0) )
	{
		value = array [index];
		ret = 1;
	}
	return ret;

}
template <typename T,int N>
T& ARRAY<T,N>::operator[]( int index)
{
		if( (index<N)&&(index>0) )
	{
		return array [index];
	}else{
		return NULL;// ERROR
/*-----
NULL IS void* and invalid initialization of non-const reference of type ‘int&’ from an rvalue of type ‘int’----
NULL IS  RVALUE
can do this----- const T& ARRAY<T,N>::operator[]( int index)
but still warning
1.h:55:10: warning: converting to non-pointer type ‘int’ from NULL [-Wconversion-null]

SO I WILL CUT THE ELSE ,THEN COMPILE PASS.
 */
 	
	}
}
template <typename T,int N>
int ARRAY<T,N>::getlen()
{
	return length;
}
#endif

1.c
#include<iostream>
#include"1.h"
using namespace std;

int main( )
{
	ARRAY<int,10>test;
	int l=test.getlen();
	cout<<"len =="<<l<<endl;
	
	if(test.setvalue(5,3))
	cout<<"index =5 value=3"<<endl;
	int value;
	if (test.getvalue(5,value))
	cout<<"index =5 value="<<value<<endl;
	
	cout<<"test[5]"<<test[5]<<endl;

	return 0;
}