C++标准规定：一个int至少和一个short一样大，一个long至少和一个int一样大，一个long long至少和一个long一样大。其中long long是c++11新定义的。
示例代码：
#include <stdio.h>
#include <iostream>using namespace std;
int main()
{
cout << "bool " << sizeof(bool) << endl;cout << "char " << sizeof(char) << endl;
cout << "wchar_t " << sizeof(wchar_t) << endl;
cout << "char16_t " << sizeof(char16_t) << endl;
cout << "char32_t " << sizeof(char32_t) << endl;cout << "short " << sizeof(short) << endl;
cout << "int " << sizeof(int) << endl;
cout << "long " << sizeof(long) << endl;
cout << "long long" << sizeof(long long) << endl;cout << "float " << sizeof(float) << endl;
cout << "double " << sizeof(double) << endl;
cout << "long double " << sizeof(long double) << endl;
return 0;
}