C++ 线程必须返回一个值

C++入门选手，学习线程时写了一小段代码，如下

```#include "stdafx.h"
#include

#include

using namespace std;

DWORD WINAPI Fun1(LPVOID lpParamter)
{
char* buf = (char *)lpParamter;
cout << int(buf) << endl;
Sleep(1000);
}

int main()
{
HANDLE hThread[2];
for (int i = 0; i < 2; i++) {
hThread[i] = CreateThread(NULL, 0, Fun1, (LPVOID)i, 0, NULL);
}
cout << "3" << endl;

Sleep(5000);
for (int i = 0; i < 2; i++) {
TerminateProcess(hThread[i],0);
CloseHandle(hThread[i]);
}
return 0;
}

在VS2015编译时报错，说“Fun1”: 必须返回一个值, 请问各位大神这是什么意思？我这程序应该怎么改？

DWORD WINAPI Fun1(LPVOID lpParamter)
{
char* buf = (char *)lpParamter;
cout << int(buf) << endl;
Sleep(1000);
return 0;
}