p107.cpp

来自「《C++编程指南（续编）》的一些程序源代码」· C++ 代码 · 共 113 行

#include <fstream.h>
#include <strstrea.h>
#include <string.h>

char * makeCopy(char * pszS)
{
	char * pszT=new char[strlen(pszS)+1];
	strcpy(pszT,pszS);
	return pszT;
}

class Student
{
public:
	Student(char * pLN,char * pFN,
		int nGrd,unsigned long ulId);

	virtual ~Student();

	void display(ostream& out)const;

protected:
	char * pLName;
	char * pFName;
	int nGrade;
	unsigned long ulID;
};

Student::Student(char * pLN,char * pFN,
				 int nGrd,unsigned long ulId)
{
	pLName=makeCopy(pLN);
	pFName=makeCopy(pFN);

	nGrade=nGrd;
	ulID=ulId;
}

Student::~Student()
{
	delete pLName;
	delete pFName;
}

void Student::display(ostream& out)const
{
	static char szGrade[]="(Grade";

	int nWidth=out.width();
	out.width(0);
	char cFill=out.fill();
	int bLeft=(out.flags()&ios::left)!=0;

	ostrstream local;
	
	local<<pLName<<" , "
		<<pFName<<" - "
		<<ulID
		<<szGrade
		<<nGrade
		<<")";

	int nLength=local.pcount();

	if(!bLeft)
	{
		int nI;
		for(nI=nLength;nI<nWidth;nI++)
		{
			out<<cFill;
		}
	}
	char * pszBuffer=local.str();
	out.write(pszBuffer,nLength);
	delete pszBuffer;

	if(bLeft)
	{
		int nI;
		for(nI=nLength;nI<nWidth;nI++)
		{
			out<<cFill;
		}
	}
}

ostream& operator<<(ostream& out,const Student& s)
{
	s.display(out);
	return out;
}

int main(int ,char **)
{
	Student s1("Moore","John",-2,789123456L);

	cout<<"Width set to 0: \n";
	cout<<"["<<s1<<"]\n";

	cout<<"\nWidth set to 80:\n";
	cout.fill('*');
	cout<<"[";
	cout.width(80);
	cout<<s1<<"]\n";

	cout<<"\nWidth set to 80 ,ios : left bit set :\n";
	cout.setf(ios::left);
	cout<<"[";
	cout.width(80);
	cout<<s1<<"]\n";

	return 0;
}