关于getline函数
用getline函数时，为什么要输入两次ENTER才能结束？？
这个是出问题的程序
#include <iostream>
#include <string>
int main()
{ using namespace std;
string str;
std::cout<<"Please input your name:\n";
getline(cin,str);
std::cout<<"Hello,"<<str<<"!!\n";
}
比如说,我们输入"virus welcome back!",但是当我们输入后按回车,程序并不运行cout语句，而是光标还在编绎窗口上闪动，要再按一下[ENTER]才会运行cout这个语句输出,最后在microsof得解:
The getline template function reads an extra character after encountering the delimiter
Article ID : 240015
Last Review : September 2, 2005
Revision : 3.0
This article was previously published under Q240015
SYMPTOMS
The Standard C++ Library template getline function reads an extra character after encountering the delimiter. Please refer to the sample program in the More Information section for details.
RESOLUTION
Modify the getline member function, which can be found in the following system header file string, as follows:
else if (_Tr::eq((_E)_C, _D))
{_Chg = true;
// _I.rdbuf()->snextc(); /* Remove this line and add the line below.*/
_I.rdbuf()->sbumpc();
break; }
Note Because the resolution involves modifying a system header file, extreme care should be taken to ensure that nothing else is changed in the header file. Microsoft is not responsible for any problems resulting from unwanted changes to the system header files.
STATUS
Microsoft has confirmed that this is a bug in the Microsoft products that are listed in the "Applies to" section. This problem was corrected in Microsoft Visual C++ .NET.
MORE INFORMATION
The following sample program demonstrates the bug:
//test.cpp
//Compiler options : /GX
#include <string>
#include <iostream>
int main () {
std::string s,s2;
std::getline(std::cin,s);
std::getline(std::cin,s2);
std::cout << s <<'\t'<< s2 << std::endl;
return 0;
}
Actual Results:
Hello<Enter Key>
World<Enter Key>
<Enter Key>
Hello World
Expected Results:
Hello<Enter Key>
World<Enter Key>
Hello World
我给大家解释下意思吧:
症状:c++的标准库模板函数getline在读到限定符后还要读取额外字符...
解决方法:else if (_Tr::eq((_E)_C, _D)) {_Chg = true; // _I.rdbuf()->snextc(); /* 把这一行注释掉,添加下一行.*/ _I.rdbuf()->sbumpc(); break; }修改系统头文件时大家要小心点...
现状:微软已经确认这是他们产品中的'臭虫'(bug),这个bug已经在Microsoft Visual C++ .NET得到修正.
案例:如上...该文件的一般路径：C:\Program Files\Microsoft Visual Studio\VC98\Include\string 注意是string文件，不是string.h,修改后问题解决
snextc:Advances the get pointer, then returns the next character.
stossc:Moves the get pointer forward one position, but does not return a character.
