cast to 'void *' from smaller integer type 'int'

", "? Is "I didn't think it was serious" usually a good defence against "duty to rescue"? Content Discovery initiative April 13 update: Related questions using a Review our technical responses for the 2023 Developer Survey. [Solved] Error "Cast from pointer to smaller type 'int' loses @Martin York: No, it doesn't depend on endiannness. If any, how can the original function works without errors if we just ignore the warning. Thanks for contributing an answer to Stack Overflow! 1.6. Casting and Ranges of Variables AP CSAwesome How to make compiler not show int to void pointer cast warnings, incompatible pointer types assigning to 'void (*)(void *)' from 'int (int *)'. I think that's what you want: // Declaration uint8_t *myData; void loop () { myData = "custom string"; } void *ptr; int n = (int)ptr; So in c++ i tried below int n = atoi (static_cast<const char*> (ptr)); This crashes when i run. Hello, I am currently working on a UDF for the heterogeneous reaction using it to describe a simple equilibrium model using the Antoine equation and vapor pressure. Referring to N1570 7.20.1.4/p1 (Integer types capable of holding object pointers): The following type designates a signed integer type with the property To learn more, see our tips on writing great answers. This will get you a pointer from a 32 bit offset: A function pointer is incompatible to void* (and any other non function pointer). If you do this, you have the thread reference a value that (hopefully still) lives in some other thread. Why are players required to record the moves in World Championship Classical games? This is not a conversion at all. A cast is a way of explicitly informing the compiler that you intend to make the conversion and that you are aware that data loss might occur, or the cast may fail at run time. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. You can use any other pointer, or you can use (size_t), which is 64 bits. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. ), For those who are interested. Thanks for contributing an answer to Stack Overflow! How to correctly cast a pointer to int in a 64-bit application? Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, @Dinesh: could you please 1) show us those. In this case, casting the pointer back to an integer is meaningless, because . My blogs h2 and other tags are in these manner. I have the following function and when I compile it under VS.NET 2005, the following compile warnings show up: Warning1warning C4311: 'type cast' : pointer truncation from 'void *' to 'long'c:\temp\testone\lib\utils.c56Warning2warning C4312: 'type cast' : conversion from 'unsigned long' to 'void *' of greater sizec:\temp\testone\lib\utils.c56, Code Snippet Please tell me error: cast from 'void*' to 'int' loses precision, How a top-ranked engineering school reimagined CS curriculum (Ep. Expressions Converts between types using a combination of implicit and user-defined conversions. Examples include conversions from smaller to larger integral types, and conversions from derived classes to base classes. I am using the UDF of the Ansys Manual Book as a base for what I intended, but I am trying to incorporate a second component to my condensable mixture, being methanol . If the data types are compatible, then Java will perform the conversion automatically known as Automatic Type Conversion, and if not then they need to be cast or converted explicitly. Even if you are compiling your program for a 32-bit computer, you should fix your code to remove these warnings, to ensure your code is easily portable to 64-bit. Were sorry. I wish your idea worked. Content Discovery initiative April 13 update: Related questions using a Review our technical responses for the 2023 Developer Survey, xcode build error: Semantic issue cast from pointer to smaller type 'int' loses information. User-defined conversions: User-defined conversions are performed by special methods that you can define to enable explicit and implicit conversions between custom types that do not have a base classderived class relationship. And, most of these will not even work on gcc4. But gcc always give me a warning, that i cannot cast an int to a void*. Not the answer you're looking for? Based on the design of this function, which modification is right. What does 'They're at four. 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). What is this brick with a round back and a stud on the side used for? What I am saying is that it would be safer to use new(5) rather than 5 and deal with it appropriately at the other end. Making statements based on opinion; back them up with references or personal experience. #, Nov 14 '05 Because C# is statically-typed at compile time, after a variable is declared, it cannot be declared again or assigned a value of another type unless that type is implicitly convertible to the variable's type. 565), Improving the copy in the close modal and post notices - 2023 edition, New blog post from our CEO Prashanth: Community is the future of AI. There's no proper way to cast this to int in general case. What is "cast from integer to pointer of different size" warning? is there such a thing as "right to be heard"? Put your define inside a bracket: #define M_TABLE_SIZE (64*1024) Now, you can do: static const void* M_OFFSET = (void*) M_TABLE_SIZE; without a problem. We have to pass address of the variable to the function because in function definition argument is pointer variable. How can I control PNP and NPN transistors together from one pin? i How do I check if a string represents a number (float or int)? Why does Acts not mention the deaths of Peter and Paul? The problem is not with casting, but with the target type loosing half of the pointer. For example, you might have an integer variable that you need to pass to a method whose parameter is typed as double. d=(double *) Hi, Write values of different data types in sequence in memory? With that declaration, you can later say: myData = "custom string"; That points the myData pointer to the address of your constant string. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. How to convert a factor to integer\numeric without loss of information? I would create a structure and pass that as void* to pthread_create. Why did DOS-based Windows require HIMEM.SYS to boot? I was able to disable this with -fms-extensions after getting this from someone on the Cpplang Slack: Looking at "DiagnosticSemaKinds.td" it shows up as err_bad_reinterpret_cast_small_int, https://github.com/llvm-mirror/clang/blob/release_50/include/clang/Basic/DiagnosticSemaKinds.td#L6193 Keep in mind that thrArg should exist till the myFcn() uses it. Going through them one by one would be very tedious and since this is an experimental project anyway, I'm happy to settle for a "hackish" workaround. 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. He should pass the address of the integer, the thread should get that address, Note: This is only appropriate is you cast the. If you are planning to use pthreads and you are planning to pass the pass function to pthread_create, you have to malloc/free the arguments you are planning to use (even if the threaded function just need a single int). C# provides the is operator to enable you to test for compatibility before actually performing a cast. Converting a void* to an int is non-portable way that may work or may not! The program will not compile without the cast. 565), Improving the copy in the close modal and post notices - 2023 edition, New blog post from our CEO Prashanth: Community is the future of AI. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Short story about swapping bodies as a job; the person who hires the main character misuses his body. Or keep using a C cast even when C++ code compiled as C++. In 64-bit programs, the size of the pointer is 64 bits, and cannot be put into the int type, which remains 32-bit in almost all systems. There are ways to prevent this: pass a dynamic allocated argument if your not the passing thread is not static or if your argument is a local variable, otherwise there is no issue. The error message mentions the diagnostic responsible for error message, e.g. Usually that means the pointer is allocated with. c - Cast int to void* - Stack Overflow Can I use my Coinbase address to receive bitcoin? Casting arguments inside the function is a lot safer. He also rips off an arm to use as a sword, Two MacBook Pro with same model number (A1286) but different year. Casting is required when information might be lost in the conversion, or when the conversion might not succeed for other reasons. Is "I didn't think it was serious" usually a good defence against "duty to rescue"? Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Connect and share knowledge within a single location that is structured and easy to search. I have read in one of old posting that don't cast of pointer which If the null hypothesis is never really true, is there a point to using a statistical test without a priori power analysis? this way you won't get any warning. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. However, if a conversion cannot be made without a risk of losing information, the compiler requires that you perform an explicit conversion, which is called a cast. It seems both static_cast and dynamic_cast can cast a base class Save this piece of code as mycast.hpp and add -include mycast.hpp to your Makefile. Thank you all for your feedback. 1) zero or one conversion from the following set: lvalue-to-rvalue conversion, array-to-pointer conversion, and function-to-pointer conversion; 2) zero or one numeric promotion or numeric conversion; 3) zero or one function pointer conversion; (since C++17) 4) zero or one qualification conversion. Remembering to delete the pointer after use so that we don't leak. Since all pointers on 64-bit Windows are 64 bits, you are growing the data size from 32 bits backto 64 bits. 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. Is there a way to disable it? It's not them. You can use a 64 bits integer instead howerver I usually use a function with the right prototype and I cast the function type : you can pass the int value as void pointer like (void *)&n where n is integer, and in the function accept void pointer as parameter like void foo (void *n); and finally inside the function convert void pointer to int like, int num = * (int *)n;. Connect and share knowledge within a single location that is structured and easy to search. "jacob navia" wrote: This question has probably been asked a million time, but here it comes When is casting void pointer needed in C? (Also, check out how it prints "5" twice), passing a unique pointer to each thread wont race, and you can get/save any kind of information in the th struct. This is an old C callback mechanism so you can't change that. I think using intptr_t is the correct intermediate here, since it's guaranteed to be large enough to contain the integral value of the void*, and once I have an integer value I can then truncate it without causing the compiler to complain. Even though what you say regarding the lifetime of the object is true, integral types are too limited for a generic API. In C#, you can perform the following kinds of conversions: Implicit conversions: No special syntax is required because the conversion always succeeds and no data will be lost. then converted back to pointer to void, and the result will compare and how to print the thread id of 2d array argument? 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. again. Making statements based on opinion; back them up with references or personal experience. These kinds of operations are called type conversions. casting from int to void* and back to int. C99 defines the types "intptr_t" and "uintptr_t" which do . By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. If a negative integer value is converted to an unsigned type, the resulting value corresponds to its 2's complement bitwise representation (i.e., If the conversion is from a floating-point type to an integer type, the value is truncated (the decimal part is removed). And in this context, it is very very very common to see programmers lazily type cast the. Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, "what happen when typcating normal variable to void* or any pointer variable?" Can you still use Commanders Strike if the only attack available to forego is an attack against an ally? Technically, these casts should therefore be valid. Why don't we use the 7805 for car phone chargers? Was Aristarchus the first to propose heliocentrism? pthread create managing values generated in function (in c), Establishing TCP socket connection between PHP client and C server on Ubuntu. The Test method has an Animal parameter, thus explicitly casting the argument a to a Reptile makes a dangerous assumption. For more information, see Polymorphism. The pointer doesn't actually point to anything, but it's the result of an earlier cast from an integer to a pointer (e.g. To perform a cast, specify the type that you are casting to in parentheses in front of the value or variable to be converted. For a complete list of all implicit numeric conversions, see the Implicit numeric conversions section of the Built-in numeric conversions article. Find centralized, trusted content and collaborate around the technologies you use most. drivers/gpu/drm/mediatek/mtk_disp_ovl_adaptor.c:415:10: warning: cast If not, check the pointer size on your platform, define these typedefs accordingly yourself and use them. Therefore, you need to change it to long long instead of long in windows for 64 bits. If the result lies outside the range of representable values by the type, the conversion causes, Otherwise, if the conversion is between numeric types of the same kind (integer-to-integer or floating-to-floating), the conversion is valid, but the value is. Thanks for contributing an answer to Stack Overflow! 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. What is this brick with a round back and a stud on the side used for? From what I read about casting in the C11 standard, my feeling is, that it is arguable to emit a warning on an explicit conversion. A nit: in your version, the cast to void * is unnecessary. Unfortunately, that hardware is 64-bit and the code contains many instances of pointer arithmetic that expects pointers to be 32-bit, i.e. Unless you have a valid address at that value, you are going to invoke undefined behaviour when try to use that pointer. void* -> integer -> void* rather than integer -> void* -> integer. I want to learn the difference between the three type cast operators: Hi, cast to void *' from smaller integer type 'int-tdecu credit scoretdecu credit score Both languages have been widely adopted by How to plot text in color? This thread has been closed and replies have been disabled. The point is (probably) that the value passed to the thread is an integer value, not really a 'void *'. eg. For integral types, this means the range of the source type is a proper subset of the range for the target type. In the best case this will give the same results as the original code, with no advantages, but in the worst case it will fail in multiple catastrophic ways (type punning, endianness, less efficient, etc.

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