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

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.

GCC has typeid.

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Originally Posted by robwhit

GCC has typeid.

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typeid is only for C++ though isn't it?

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Originally Posted by cpjust

typeid is only for C++ though isn't it?

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True, the typeid is used only in C++.

ssharish

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.

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Mats

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