C++ like vs C like casts?

Question

Possible Duplicate:
Regular cast vs. static_cast vs. dynamic_cast

i've been using C-like casts since i've been programming:

class* initializedClassInstance;
void* test = (void*) initializedClassInstance;

and i've been told somewhere that i should get used to C++ casts (static_cast, dynamic_cast...).

Is there a reason to prefer one over the other (C++ over C style)? There is a difference between static cast and dynamic cast, right? But what is it?

Thanks!

score 4 · Accepted Answer · answered Aug 06 '12 at 08:51

4

C-style casts are unsafe.

C++-style casts behave in another way. static_cast will give you a compilation error if it can't make the cast. dynamic_cast on fail will cast to NULL if you are casting pointers, and throw an exception otherwise.

So this allows you to write a safer code.

answered Aug 06 '12 at 08:51

SingerOfTheFall

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dynamic_cast will return NULL only for pointers. For references an exception will be thrown – Andrew Aug 06 '12 at 08:53
@Andrew, yes, that's a good point, thanks. – SingerOfTheFall Aug 06 '12 at 08:55
@KillianDS, that's what I meant. A good example for it is pointer casting, which allows you to cast almost anything. – SingerOfTheFall Aug 06 '12 at 08:57
Great, thanks for the fast answer! – Xavier Arias Botargues Aug 06 '12 at 08:59
@SingerOfTheFall: my comment was more about the lack of explanation as to why C-style casts are unsafe. Without proper explanation this is (imo) a terrible answer. – KillianDS Aug 06 '12 at 09:14

score 1 · Answer 2 · edited Aug 06 '12 at 08:52

1

Yes, there is. It give you checks. static_cast gives you compile time checks and dynamic_cast gives you runtime checks for example.

You can read more about casts here

edited Aug 06 '12 at 08:52

c00kiemon5ter

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answered Aug 06 '12 at 08:48

Andrew

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C++ like vs C like casts?

2 Answers2