The mapping in pointer<->integer casts is implementation defined, but the intent was that if the pointer type is large enough and isn't forcefully aligned (, But that's different. The 32 remaining bits stored inside int are insufficient to reconstruct a pointer to the thread function. The main point is: a pointer has a platform dependent size. Press question mark to learn the rest of the keyboard shortcuts. Floating-point conversions But you seem to suggest by your answer that the user can pass 5 to pthread_create and then perform the above cast to get it back. Is it plausible for constructed languages to be used to affect thought and control or mold people towards desired outcomes? You are right! Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2, Xcode 5 and iOS 7: Architecture and Valid architectures, xcode build error: Semantic issue cast from pointer to smaller type 'int' loses information, Issues in handling touches on subviews(uiviews) in UIScrollView, Architecture linking error after Xcode 5.1 upgrade, iOS 7.1 gives error after updating to Xcode 5.1, Linker error in Xcode 5.1 with cocos2d-x 3 beta 2. Taking the above declarations of A, D, ch of the . You can use a 64 bits integer instead howerver I usually use a function with the right prototype and I cast the function type : vegan) just to try it, does this inconvenience the caterers and staff? SCAN_PUT(ATTR, NULL); Basically its a better version of (void *)i. The difference between the phonemes /p/ and /b/ in Japanese. Does Counterspell prevent from any further spells being cast on a given turn? Does Counterspell prevent from any further spells being cast on a given turn? The only alternative is really to take time and fix all 64-bit code issues, of which there may be some non-trivial issues. What I am trying to do in that line of code is check to make sure each character in my string is alphabetical. I'm only guessing here, but I think what you are supposed to do is actually pass the address of the variable to the function. All character types are to be converted to an integer. Identify those arcade games from a 1983 Brazilian music video, Relation between transaction data and transaction id, The difference between the phonemes /p/ and /b/ in Japanese. The dynamic_cast<>operator provides a way to check the actual type of a pointer to a polymorphic class. to the original pointer: The following type designates an unsigned integer type with the Offline ImPer Westermark over 11 years ago in reply to Andy Neil Except that you sometimes stores an integer in the pointer itself. When is casting void pointer needed in C? whether it was an actual problem is a different matter though. Using Kolmogorov complexity to measure difficulty of problems? As Ferruccio said, int must be replaced with intptr_t to make the program meaningful. For example, if you want to store a 'long' value into a simple integer then you can type cast 'long' to 'int'. All float types are to be converted to double. Are there tables of wastage rates for different fruit and veg? Making statements based on opinion; back them up with references or personal experience. ", "!"? What I am trying to emphasis that conversion from int to pointer and back again can be frough with problems as you move from platform to platform. Find centralized, trusted content and collaborate around the technologies you use most. "clang" "-Ilib\libopenvswitch.a.p" "-Ilib" "-I..\lib" "-I." So the compiler is very picky here and the correct solution to make the code compile again and still let it show the exact same behavior like in Xcode 5.0 is to first cast to an integer type with a size that matches the one of a pointer and to then do a second cast to the int that we actually want: ids [i] = (int) (size_t)touch; // OK: lvalue denoting the original d object, // UB: the b subobject is not a base class subobject, // 6. array-to-pointer followed by upcast, https://en.cppreference.com/mwiki/index.php?title=cpp/language/static_cast&oldid=147983, when converting a 'pointer to object' to 'pointer to, the conversion from floating-point values, the conversion from bit-fields to rvalue references, the conversion from integral or enumeration values to enumeration, the conversion from integral or enumeration values to, the conversion from a member of base class type to, a standard-layout class object with no data members, a non-standard-layout union object and a non-static data, for base-to-derived pointer conversions and, the conversion to enumeration types with fixed underlying type, a standard-layout class might have a non-pointer-interconvertible, If the underlying type is not fixed, the behavior is undefined if the value of, If the underlying type is fixed, the result is the same as, one is a union object and the other is a non-static data member of that object, or. Can I tell police to wait and call a lawyer when served with a search warrant? Even though what you say regarding the lifetime of the object is true, integral types are too limited for a generic API. Using an integer address (like &x) is probably wrong, indeed each modification you will execute on x will affect the pass behaviour. ncdu: What's going on with this second size column? To subscribe to this RSS feed, copy and paste this URL into your RSS reader. I am compiling this program in linux gcc compiler.. My code is GPL licensed, can I issue a license to have my code be distributed in a specific MIT licensed project? To be honest, I think, clang is too restrictive here. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. The preprocesor absolutely will not perform arithmetic. Fork 63. Do roots of these polynomials approach the negative of the Euler-Mascheroni constant? Euler: A baby on his lap, a cat on his back thats how he wrote his immortal works (origin?). Not the answer you're looking for? What is the purpose of this D-shaped ring at the base of the tongue on my hiking boots? then converted back to pointer to void, and the result will compare Please tell me error: cast from 'void*' to 'int' loses precision, How Intuit democratizes AI development across teams through reusability. Netdev Archive on lore.kernel.org help / color / mirror / Atom feed * [mst-vhost:vhost 5/52] drivers/block/virtio_blk.c:539:21: warning: assignment to 'void *' from . Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. What can a lawyer do if the client wants him to be acquitted of everything despite serious evidence? 7.1 New Cast Operations The C++ standard defines new cast operations that provide finer control than previous cast operations. In the case of Widening Type Casting, the lower data type (having smaller size) is converted into the higher data type (having larger size). this way you won't get any warning. - the incident has nothing to do with me; can I use this this way? Converting one datatype into another is known as type casting or, type-conversion. 10) A prvalue of type pointer to void (possibly cv-qualified) can be converted to pointer to any object type. what happens when we typecast normal variable to void* or any pointer variable? But I don't want to edit code in "EAGLView.mm" because it's a "library file". Thanks for contributing an answer to Stack Overflow! If the object expression refers or points to is actually a base class subobject of an object of type D, the result refers to the enclosing object of type D. Otherwise, the behavior is undefined: When the target type is bool (possibly cv-qualified), the result is false if the original value is zero and true for all other values. Share Improve this answer Follow answered May 6, 2018 at 7:24 Rahul (void *)i Error: cast to 'void *' from smaller integer type 'int' PS: UBUNTUCLANG3.5 clang -O0 -std=gnu11 -march=native -lm -lpthread pagerank.c -o pagerank c pthreads 4 10.3k 2 21 2015-06-05 It is commonly called a pointer to T and its type is T*. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. He should pass the address of the integer, the thread should get that address, Note: This is only appropriate is you cast the. This is why you got Error 1 C2036, from your post. */void **MatrixIB (unsigned long x, unsigned long y, int size){ void *ptr; void **returnPtr; register unsigned long i, j; returnPtr = (void **) malloc (x * sizeof(void *)); ptr = (void *) malloc (x * y * size); for (i=0, j=0; j returnPtr[j] = (void *) (ptr + i); // <<< Compile Errors, Error1error C2036: 'void *' : unknown sizec:\temp\testone\lib\utils.c57, 2> returnPtr[j] = (void *) ((long*)ptr + i); // <<< No compile errors, 3> returnPtr[j] = (void *) ((char*)ptr + i); // <<< No compile errors. To learn more, see our tips on writing great answers. this way you won't get any warning. Do roots of these polynomials approach the negative of the Euler-Mascheroni constant? The result is the same as implicit conversion from the enum's underlying type to the destination type. ../lib/odp-util.c:5603:13: note: expanded from macro 'SCAN_PUT' long guarantees a pointer size on Linux on any machine. Connect and share knowledge within a single location that is structured and easy to search. Your first example is risky because you have to be very careful about the object lifetimes. From that point on, you are dealing with 32 bits. The cast back to int * is not, though. If you need to keep the returned address, just keep it as void*. The OP wanted to convert a pointer value to a int value, instead, most the answers, one way or the other, tried to wrongly convert the content of arg points to to a int value. GitHub Skip to content Product Solutions Open Source Pricing Sign in Sign up smadaminov / ovs-dpdk-meson-issues Public Notifications Fork 1 Star 1 Code Issues 66 Pull requests Actions Projects 1 Security Insights New issue Error while setting app icon and launch image in xcode 5.1. Making statements based on opinion; back them up with references or personal experience. What happens if you typecast as unsigned first? Identify those arcade games from a 1983 Brazilian music video. (int*)Pc = pa; After the execution of the above code all the three pointers, i.e., Pa, Pd, and Pc, point to the value 150. The correct answer is, if one does not mind losing data precision. Connect and share knowledge within a single location that is structured and easy to search. How do I force make/GCC to show me the commands? Returns a value of type new-type. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy.