[Turn] C ++ using std :: noskipws read whitespace characters

How to read a blank character input stream it?

In the standard flow, there is a skipws tag, the default is set, indicating that when the blank character reading, they will be discarded. Use std :: noskipws manipulator can clear this flag:

cin >> std::noskipws;

A case:

#include <iostream>
#include <sstream>

int main()
{
        char a, b, c;

        std::istringstream iss("  123");
        iss >> std::skipws >> a >> b >> c;      // 忽略掉前面的空白字符，PS: 默认std::skipws是置位的
        std::cout << a << b << c << std::endl; // 123

        iss.seekg(0);
        iss >> std::noskipws >> a >> b >> c; // 不忽略空白字符，将其读取
        std::cout << a << b << c << std::endl; // ..1

        return 0;
}

Reference: http://www.cplusplus.com/reference/ios/noskipws/

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Author: Demon90s
Source: CNBLOGS
Original: https://www.cnblogs.com/demon90s/p/7704502.html
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