Thread: Datatype

  1. #1
    Registered User ssharish2005's Avatar
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    Datatype

    Hello all, I was just wondering if there is anyway to find, what datatype a variable is? I mean like without using the sizeof operator. May be sometimes even the sizeof operator wouldn't be like more helpful at all in finding what datatype a variables is, depends on what compiler used and stuff.

    But I was just wondering if we could. I tried it all possible way. Well at least, to my knowledge.

    Thanks for your help guys

    ssharish

  2. #2
    and the hat of sweating
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    If you wrote it, you should know what the datatype is.
    If you mean you're getting a void* and you want to find out what it was before it was cast to void*, then I think you're out of luck. Switch to C++ and use templates in that case.

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    GCC has typeid.

  4. #4
    and the hat of sweating
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    Quote Originally Posted by robwhit View Post
    GCC has typeid.
    typeid is only for C++ though isn't it?

  5. #5
    Registered User ssharish2005's Avatar
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    Quote Originally Posted by cpjust View Post
    typeid is only for C++ though isn't it?
    True, the typeid is used only in C++.

    ssharish

  6. #6
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    Perhaps you can provide some more explanation of what you actually want to achieve.

    For purposes of macros etc, you can (in gcc) use typeof(x), where x is some variable declared earlier in the code. But for most things, you shouldn't really have to care - you should KNOW.

    There are cases where you would want to pass some "could cointain anything" type of data - in which case a struct and union combination would be the correct solution.

    But without understanding your problem better, I don't think it's possible to suggest a correct solution.

    --
    Mats
    Compilers can produce warnings - make the compiler programmers happy: Use them!
    Please don't PM me for help - and no, I don't do help over instant messengers.

  7. #7
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    Yeah that's what I was thinking of. typeof.

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