为何main()里定义的const对象不能为其他文件所用解决方案

//a.h
#ifndef _A_H_
#define _A_H_

#include "b.h"

extern const int ArrayCount;

typedef struct
{
    int *a;   
    int data;      
}DataType;

extern void Init( DataType *G );

//a.cpp
#include "a.h"

void Init( DataType *G )
{
    G->data = 0;

    G->a = new int [ArrayCount];

    for ( int i = 0; i < ArrayCount; i++ )
    {
        G->a[i] = i;
    }
}

//b.h
#ifndef _B_H_
#define _B_H_

extern const int ArrayCount;

extern void Function( int &val2 );

#endif

//b.cpp
#include "b.h"

void Function( int &val2 )
{
    int x = 16;
    x *= x;

    val2 = x;
}

//main.cpp
#include <cstdio>
#include "a.h"
#include "b.h"

int main( void )
{
    int nVal = 0;

    Function( nVal );

    const int ArrayCount = 10;

    DataType x;

    Init(&x);

    for ( int i = 0; i < ArrayCount; i++ )
    {
        printf( "%d ", x.a[i] );
    }

    printf("\n");
    return 1;
    
}