C++初探_自定义名称空间

代码：

#include <iostream>

namespace Jack {
    double pail;
    void fetch();
    int pal; //分号分割变量
}
namespace Jill {
    double bucket;
    double fetch;
    int pal;
}

int main()
{
    Jack::pal = 12.34;
    Jill::pal = 23.45;

    using Jill::fetch;
    fetch = 34.56;

}