Thread: ifstream error

  1. #1
    Registered User
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    Apr 2007
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    ifstream error

    I want the following function to open a file which the name of the file is stored in file_name. However, when I tried to compile it, I received no matching function for call to 'std::basic_ifstream...... error. When I replaced the file_name with actual name of the file like "data.txt", it compiled without error. Could someone please help me out? I need the users to be able to type in the file name. Thanks in advance.

    Code:
    void retrieve_file(string file_name)
          {
                string line;
                unsigned int input_index;
                string input_entry;
                
                
                ifstream input_file (file_name);
                if(input_file.is_open())
                {
                   """ """ """
                }
           }

  2. #2
    Officially An Architect brewbuck's Avatar
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    ifstream can only take a C-style string as a filename. You should use:

    Code:
    ifstream input_file (file_name.c_str());

  3. #3
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    Thanks

  4. #4
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    Thankfully a string based constructor has been added to the C++0x draft so this won't be an issue in the future.

  5. #5
    The superhaterodyne twomers's Avatar
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    >> Thankfully a string based constructor has been added to the C++0x draft so this won't be an issue in the future.

    Woo! That's something that's been bugging me for ages! that .c_str() ... where is this draft, Daved?

  6. #6
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    Here's the post from CornedBee where I got the link. I just downloaded it from there:

    http://cboard.cprogramming.com/showp...05&postcount=5

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