LPCTSTR ends at space

This is a discussion on LPCTSTR ends at space within the C++ Programming forums, part of the General Programming Boards category; I'm trying to convert STD:: basic_string<TCHAR> to LPCTSTR. It works, but the result ends at the first space in the ...

  1. #1
    Registered User Vick jr's Avatar
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    LPCTSTR ends at space

    I'm trying to convert STD:: basic_string<TCHAR> to LPCTSTR. It works, but the result ends at the first space in the original string.

    Code:
    basic_string<TCHAR> strOutput;
    basic_stringstream<TCHAR>  buff;
    buff << "Camera pos: ("<<camerax<<", "<<cameray<<", "<<cameraz<<")";
    buff>>strOutput;
    output=(LPCTSTR)strOutput.c_str();
    I know the conversion works because I output="Camera". If I replace all the spaces with underscores then the entire thing works. I suppose that's acceptable, but is there any way to get the spaces?

    (or a better way to convert? I still need to be able to add string versions of my variables easily, like with the stringStream above, which automatically converts my floats to strings)


    Note: the reason I'm doing this is so I can send output to the directx LPD3DXFONT->DrawText() function. Is it possible that this function just doesn't like spaces?
    Last edited by Vick jr; 05-20-2010 at 05:39 PM.

  2. #2
    Registered User Codeplug's Avatar
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    First, a review of TCHAR's - LPCTSTR operations/ convertion

    I don't recommend TCHAR's, but just to correct the above code:
    You have to use the TEXT("") macro for TCHAR string literals. This will put the necessary "L" in front of the literal in case TCHAR resolves to wchar_t.

    >> output=(LPCTSTR)strOutput.c_str();
    c_str() already returns the correct type - you shouldn't have to cast it.

    Consider doing to your work with either char or wchar_t strings and just call the "A" or "W" directx functions.

    gg

  3. #3
    Registered User jeffcobb's Avatar
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    Quote Originally Posted by Codeplug View Post
    First, a review of TCHAR's - LPCTSTR operations/ convertion

    I don't recommend TCHAR's, but just to correct the above code:
    You have to use the TEXT("") macro for TCHAR string literals. This will put the necessary "L" in front of the literal in case TCHAR resolves to wchar_t.

    >> output=(LPCTSTR)strOutput.c_str();
    c_str() already returns the correct type - you shouldn't have to cast it.

    Consider doing to your work with either char or wchar_t strings and just call the "A" or "W" directx functions.

    gg
    He was getting confused with the Microsoft CString class where such a thing works
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  4. #4
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    No need for the LPCSTR conversions.

    Input streaming operations (like buff>>strOutput) stop at the first whitespace by default unless end of stream is reached first.

    basic_stringstream has a method named str() which returns a string object that contains a copy of the stream buffer. So try strOutput = buff.str();
    Right 98% of the time, and don't care about the other 3%.

  5. #5
    Registered User Vick jr's Avatar
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    Quote Originally Posted by grumpy View Post
    No need for the LPCSTR conversions.

    Input streaming operations (like buff>>strOutput) stop at the first whitespace by default unless end of stream is reached first.

    basic_stringstream has a method named str() which returns a string object that contains a copy of the stream buffer. So try strOutput = buff.str();
    Ah ha! That explains the spaces. I should have remembered that streams end with whitespace. I've had problems with that before. Thank you!

    Now, using that function and regular std::string

    Code:
    string strOutput;
    stringstream  buff;
    buff << "Camera pos: ("<<camerax<<", "<<cameray<<", "<<cameraz<<")";
    strOutput=buff.str();
    
    D3DXCreateTextureFromFileA(...,strOutput,...);

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