Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, @Dinesh: could you please 1) show us those. Using Kolmogorov complexity to measure difficulty of problems? 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. Asking for help, clarification, or responding to other answers. ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ If the destination type is bool, this is a boolean conversion (see below). If you preorder a special airline meal (e.g. The only exception is exotic systems with the SILP64 data model, where the size of int is also 64 bits. how to cascade 2d int array to 2d void pointer array? It solved my problem too. Are there tables of wastage rates for different fruit and veg? Can anybody explain how to pass an integer to a function which receives (void * ) as a parameter? If you convert (void*) to (long) no precision is lost, then by assigning the (long) to an (int), it properly truncates the number to fit. static const void* M_OFFSET = (void*)64*1024; Since gcc compiles that you are performing arithmetic between void* and an int ( 1024 ). The bigint data type is intended for use when integer values might exceed the range that is supported by the int data type.. bigint fits between smallmoney and int in the data type precedence chart.. What I am trying to do in that line of code is check to make sure each character in my string is alphabetical. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. You need to cast the void* pointer to a char* pointer - and then dereference that char* pointer to give you the char that it points to! The best way is, if one can, do not do such casting, instead, if the same memory address has to be shared for pointer and int (e.g. This page has been accessed 1,655,678 times. @Artelius: Which, presumably, is exactly what Joshua did: A C++ reinterpret cast will not solve the problem. Does melting sea ices rises global sea level? tialized" "-Wno-format" "-Wno-incompatible-pointer-types" "-Werror" "-dM" "-U_MSC_VER" "-D_TIMESPEC_DEFINED" "-D_CRT_NONSTDC_NO_DEPRECATE -D_CRT_SECURE_NO_WA Making statements based on opinion; back them up with references or personal experience. FAILED: lib/libopenvswitch.a.p/odp-util.c.obj As with all cast expressions, the result is: Two objects a and b are pointer-interconvertible if: static_cast may also be used to disambiguate function overloads by performing a function-to-pointer conversion to specific type, as in. To be honest, I think, clang is too restrictive here. Connect and share knowledge within a single location that is structured and easy to search. Again, all of the answers above missed the point badly. However the actual code in question contains an explicit c-style cast to int. Connect and share knowledge within a single location that is structured and easy to search. void* -> integer -> void* rather than integer -> void* -> integer. I am compiling this program in linux gcc compiler.. Well it does this because you are converting a 64 bits pointer to an 32 bits integer so you loose information. 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 . Half your pointer will be garbage. Can I tell police to wait and call a lawyer when served with a search warrant? The problem was there before, you just are being notified of it. All float types are to be converted to double. For integer casts in specific, using into() signals that . 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: I am using size_t here, because it is always having the same size as a pointer, no matter the platform. And in the function you get the value of the pointer by using the dereference operator *: Please read why glib provide macros for this kind of conversions, there's no need to repeat the text here. How to use Slater Type Orbitals as a basis functions in matrix method correctly? [] ExplanatioUnlike static_cast, but like const_cast, the reinterpret_cast expression does not compile to any CPU instructions (except when converting between integers and pointers or on obscure architectures where pointer representation depends on its type). On a 64-bit Windows computer, 'long' is a 32-bit type, and all pointers are 64-bit types. It is purely a compile-time directive which instructs the compiler to treat expression as if it had . Replacing broken pins/legs on a DIP IC package, AC Op-amp integrator with DC Gain Control in LTspice. A cast specifies a conversion from one type to another. "-I.." "-Iinclude\openflow" "-I..\include\openflow" "-Iinclude\openvswitch" "-I..\include\openvsw reinterpret_cast<void *>(42)). An object pointer (including void*) or function pointer can be converted to an integer type using reinterpret_cast. To cast such pointers to 32-bit types and vice versa special functions are used: void * Handle64ToHandle ( const void * POINTER_64 h ) void * POINTER_64 HandleToHandle64 ( const void *h ) long HandleToLong ( const void *h ) unsigned long HandleToUlong ( const void *h ) Basically its a better version of (void *)i. GitHub. ), For those who are interested. Why does Mister Mxyzptlk need to have a weakness in the comics? for (i=0, j=0; j to define it. Whats the grammar of "For those whose stories they are"? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. to your account, [87/252] Compiling C object lib/libopenvswitch.a.p/odp-util.c.obj Not the answer you're looking for? As a result of the integer division 3/2 we get the value 1, which is of the int type. From the question I presume the OP does. If int is no larger than pointer to void then one way to store the value is by simply copying the bytes: int i . Connect and share knowledge within a single location that is structured and easy to search. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. So, when you cast a (void*) to (long), you are losing 32 bits of data in the conversion. All character types are to be converted to an integer. The 32 remaining bits stored inside int are insufficient to reconstruct a pointer to the thread function. Here is my code: I already tried (void*)M_TABLE_SIZE but then I get an error that I cannot use the * operator. There exist two main syntaxes for generic type-casting: functional and c-like: 1 2 3 4 double x = 10.3; int y; y = int (x); // functional notation y = (int) x; // c-like cast notation The functionality of these generic forms of type-casting is enough for most needs with fundamental data types. Do new devs get fired if they can't solve a certain bug? Why is this sentence from The Great Gatsby grammatical? By clicking Sign up for GitHub, you agree to our terms of service and The text was updated successfully, but these errors were encountered: You signed in with another tab or window. Next, when doing pointer arithmetic, the addition operation will use the pointer's type to determine how many bytes to add to it when incrementing it. In the first example, the variable c1 of the char type is converted to a temporary variable of the int type, because the second operand in the division operation, the constant 2, is of the higher type int. The dynamic_cast<>operator provides a way to check the actual type of a pointer to a polymorphic class. Since gcc compiles that you are performing arithmetic between void* and an int (1024). How Intuit democratizes AI development across teams through reusability. actually no, as int my be a smaller type than a pointer ;-) But, of course with int64_t it works fine. You can fix this error by replacing this line of code. Yeah, the tutorial is doing it wrong. Can Martian regolith be easily melted with microwaves? The following program casts a double to an int. Please note that the error I am receiving is "cast to smaller integer type 'int' from 'string' (aka 'char *')" referencing line of code: while (isalpha(residents[i].name) == 0). ncdu: What's going on with this second size column? Getting Command /bin/sh failed with exit code 65 Error with Xcode 5.1 . How do I align things in the following tabular environment? The problem just occur with Xcode 5.1. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, You should be doing int x = *((int *)arg); You are casting from void * to int that is why you get the warning.