I come across a lot of dyn_cast in a codebase I am working on.
Is it the same thing as dynamic_cast ? or something different ? I searched a bit but couldn't find much info..
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5`dyn_cast
()` is an [operator from the LLVM](http://llvm.org/docs/ProgrammersManual.html#isa), and behaves like the standard C++ `dynamic_cast – wkl Aug 23 '12 at 00:40` operator. -
ah ok makes sense cause I am working on something related to llvm. thanks – Cemre Mengü Aug 23 '12 at 00:41
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1@birryree: You should post this as an answer. – Keith Thompson Aug 23 '12 at 00:43
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http://llvm.org/docs/ProgrammersManual.html – Lwin Htoo Ko Aug 23 '12 at 00:44
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dyn_cast is part of the LLVM API (and also is the first, second, third, etc.. hit on google) works just like dynamic_cast, however, one difference is that the class doesn't require a v-table like dynamic_cast. Please see the manual for more info.
Jesse Good
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Actually, it is llvm::dyn_cast_or_null which is equivalent to dynamic_cast.
These will produce a null pointer if passed a null pointer, whereas llvm::dyn_cast will bail.
Christer Swahn
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Both `llvm::dyn_cast_or_null` and `llvm::dyn_cast` will return a null if the value is not of the required type. The difference between then is whether they accept nulls as arguments. – Emoun Oct 11 '21 at 12:28
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Good point about how `llvm::dyn_cast_or_null` can accept a null pointer as argument like `dynamic_cast`. However, the point about not requiring the class to have a v-table still holds. Thus, `llvm::dyn_cast_or_null` and `dynamic_cast` are not equivalent. – Hari May 18 '23 at 07:45