关于cout.setf(ios_base ::showpoint)的一个问题
#include <iostream>using namespace std;
int main()
{
float a=2.4;
cout <<"before showpoint,a="<<a<<endl; //output 2.4
ios_base ::fmtflags back=cout.setf(ios_base ::showpoint);
cout <<"after showpoint,a="<<a<<endl; //output 2.400000
cout.setf(back);
cout<<"after restore , a="<<a<<endl; //还是 2.400000
system ("pause");
return 0;
}
为什么执行了cout.setf(back);后还是输出2.400000?