zero(char (&arr) [10]);  //10個(gè)元素的數(shù)組, sizeof(arr)==10*sizeof(char)==10
zero(char arr[]);  //arr退化為指針, sizeof(arr)==sizeof(char*)
zero(char *arr, size_t n);  //處理任意含n個(gè)char的連續(xù)內(nèi)存
 
void main(){
    char* pc = new char[10];
    zero(pc,10);  //連續(xù)內(nèi)存，但不是數(shù)組
}

template<size_t N>
void zero(char (&arr)[N]) ;

char aa[10];
zero(aa,20);

char aa[10];
std::array<char,10> bb;
 
zero(aa,sizeof(aa)/sizeof(aa[0]));
zero(bb.data(),bb.size());

void zero( std::span<char> sp ){
    size_t n = sp.size();
    sp[n-1]=0; //當(dāng)數(shù)組越界時(shí)，仍可能引發(fā)事故。
}
 
char aa[10];
std::array<char,10> bb;
  
zero(aa);
zero(bb);  //簡(jiǎn)化，統(tǒng)一

// This file is a "Hello, world!" in C++ language by GCC for wandbox.
#include <iostream>
#include <cstdlib>
#include <array>
 
template<class T>
class span{
public:
    template<size_t N>
    span(T (&arr)[N]){
        arr_ = arr;
        n_ = N;
    }
    
    template<size_t N>
    span(std::array<T,N>& arr){
        arr_ = arr.data();
        n_ = N;
    }
    
    span(T* arr,size_t n){
        arr_ = arr;
        n_ = n;
    }
    
    T* data(){ return arr_;}
    size_t size(){ return n_;}
    
private:
    T* arr_;
    size_t n_;
};
 
void zero( span<char> sp ){
    
    char* arr = sp.data();
    size_t n = sp.size();
    arr[n-1]=0;
}
 
int main()
{
    char aa[10];
    std::array<char,10> bb;
    
    size_t n=10;
    char* pc = new char[n];
    zero(aa);
    zero(bb);
    zero({pc,n});
   
}