"std::stringstream" unexpected behavior (simple example)

This is a discussion on "std::stringstream" unexpected behavior (simple example) within the C++ Programming forums, part of the General Programming Boards category; hi Guys, i'm puzzled by the values i'm getting back from stringstream Code: #include <sstream> #include <iostream> int main(int argc, ...

  1. #1
    Registered User
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    "std::stringstream" unexpected behavior (simple example)

    hi Guys,

    i'm puzzled by the values i'm getting back from stringstream

    Code:
    #include <sstream>
    #include <iostream>
    
    int main(int argc, char* argv[])
    {
        std::stringstream ss("1");
        int x;
        ss >> x;
        std::cout <<"(" <<x <<")";
    
        ss.str("1");
        int y;
        ss >> y;
        std::cout <<"(" <<y <<")";
    
        return 0;
    }
    output is!
    Code:
    (1)(-1)
    i was of course expecting:
    Code:
    (1)(1)
    it's causing problems in one of my programs.
    anyone got an explanation?

    (i'm using code::blocks with mingw if that matters)

  2. #2
    C++ Witch laserlight's Avatar
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    Do a ss.clear() to clear the error state of the stringstream before using str().
    Quote Originally Posted by Bjarne Stroustrup (2000-10-14)
    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.
    Look up a C++ Reference and learn How To Ask Questions The Smart Way

  3. #3
    Registered User
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    thank you!
    that was it. everything is working now. i didn't expect any error state in such a simple case.

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