d=dynamic_cast
(b); Would salt mines, lakes or flats be reasonably found in high, snowy elevations? I am still in the search of a compiler option in GCC/Clang. Warnings are just that -- warnings. class base The type int(32bit) is not big enough to hold 64 bit pointer void*. Reinterpret cast from pointer to integer is defined only in the case where the integer can represent all of the All rights reserved. I just came across some code doing the same thing - yeah, its not great but needed a solution to get it compiling on 64 bit machines - thanks for the heads-up! Im using Ubuntu with G++ installed. Connect and share knowledge within a single location that is structured and easy to search. You are just making it bigger by tricking the compiler and the ABI. 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. make install The issue is that, in 32bits, an int (which is a 32bit integer) will hold a pointer value. It is a valid use case to cast things from void* to integer types if you have a generic function that takes (void *) because the a user can pass their own data which may be a pointer or an integer into it. As defined by the current C++ standard, there is no integer type which is guaranteed to hold a pointer. On a slightly related note, embedding Python is not a suitable beginner's project. But there be some circumstances where one can safely downcast pointer (e.g. difference between two pointers). What do you think will happen when you try to store a 64-bit wide pointer into a 32-bit integer? +1 for referencing intptr_t. In the United States, must state courts follow rulings by federal courts of appeals? warning: cast from void* to int loses precision [-fpermissive] warning:implicit conversion loses integer precision:int to unsigned short -- C integer promotion cast from pointer to smaller type int loses information NDK While the pointer points to an address in the first 4 GB, the upper 32 bits will be 0 and you won't lose any data. Books that explain fundamental chess concepts. But that doesn't change the fact that this. Casting a pointer to an int is horrible from a portability perspective. But then you need to cast your arguments inside your thread function which is quite unsafe cf. Your code is broken. It won't become any less broken by ignoring the warnings the compiler gives you. What do you think will happen when you try By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. When it is cast to an integer (int)OriginalChar the result is the address of the array, as an int. # I have used My question is simple: When should I use a long, int, char, unsigned/signed variables?? This is not even remotely "the correct answer". In my case, I was using a 32-bit value that needed to be passed to an OpenGL function as a void * representing an offset into a buffer. At what point in the prequels is it revealed that Palpatine is Darth Sidious? Real-world advantage of namespace aliases vs defines, C++ expected primary-expression before "int", generating random numbers in C++ using TR1 /dev/random (resilient to <1 second runs). Any examples of when things like "unsigned", "long", "short" etc Hi guys int main() Making statements based on opinion; back them up with references or personal experience. 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. I disagree with the one-sidedness of all these answers. From the question I presume the OP does. You cannot just cast the 32-bit variable to a pointer, because that pointer on a 64-bit machine is twice as long. Devesh. 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. Better way to check if an element only exists in one array. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. public: For C++ I'd normally advise using C++ I/O with the << operator (and for pointers you have to be careful with char*, which has an overload treating it as a pointer to a string), but that might not be available in this case. If the sizes are different then endianess comes into play. But for a larger type to int, it works fine. This returns the first 32 bits of the pointer which may be the top or the bottom depending on big versus little endian, as comment #2 said. Terrible solution. Undefined behavior of constexpr static cast from int to scoped enum with non-fixed underlying type compiles in C++17, retrieving int value from void sub function to function in C++, Compile error : cast void * failed in C/C++. Asking for help, clarification, or responding to other answers. Is energy "equal" to the curvature of spacetime? It won't become any less broken by ignoring the warnings the compiler gives you. How do I work around the GCC "error: cast from SourceLocation* to int loses precision" error when compiling cmockery.c? long guarantees a pointer size on Linux on any machine. Is energy "equal" to the curvature of spacetime? Or stay on the 32-bit platform that the code currently works on. {cout<<"from der\n";} listen(2): listen for connections on socket - Linux man page #include I provide the solution if there is a dire need to cast pointer into integer. On 64-bit systems, the cast doesn't work. For example: You will get an error: cast from char* to int loses precision [-fpermissive]. You will get an error: cast from char* to int loses precision [-fpermissive] To solve this in line 5 instead of (int)pLocation3 we have to use (int64_t)pLocation3 as a 64bit machine Windows has 32 bit long only on 64 bit as well. Counterexamples to differentiation under integral sign, revisited. C++ deleting children basing on parent's pointer, Sending files over TCP sockets C++ | Windows. Discussion at stackoverflow.com. And the previous answers say it well. How do I parse a string to a float or int? Casting from pointer to any data maybe useful in user-defined callbacks. If the reason for the cast is to do pointer arithmetic with byte granularity, then the best way is probably to cast to a (char const *) and do the math with that. Also, think why it is required? This is the valid case where this is required. Some platforms will have an intptr_t, but this is not a standard feature of C++. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. Error: cast from void* to int loses precision. Asking for help, clarification, or responding to other answers. {cout<<"from base\n";} Fortunately, you've shown us the line with the error. Something can be done or not a fit? How create a simple program using threads in C? Discussion at bytes.com. And how to get the value they. printf("%d",c); }; {cout<<"from base\n";} testhandlerint4. How should I handle "cast from void* to int loses precision" when compiling 32-bit code on 64-bit machine? Something else about the call, typically another argument, tells the function if the pointer argument is actually a pointer to some data, or just an integer that has been 'upcast' to a pointer. }; You can try to use intptr_t for best portability instead of int where pointer casts are required, such as callbacks. . Aug 27, 2016 at 9:39am. The OP tried this directly, and your answer still does it, except that it converts to 64-bit integer first, and then to 32-bit integer. https://www.cnblogs.com/wajika/p/6516379.html, VSVShttps://docs.microsoft.com/zh-cn/visualstudio/ide/?view=vs-2022, 1*pa*p, He should pass the address of the integer, the thread should get that address, Note: This is only appropriate is you cast the. How does the Chameleon's Arcane/Divine focus interact with magic item crafting? At what point in the prequels is it revealed that Palpatine is Darth Sidious? There's no proper way to cast this to int in general case. Suppressing the warnings are a bad idea, but there may be a compiler flag to use 64-bit ints, depending on your compiler and architecture, and th Find centralized, trusted content and collaborate around the technologies you use most. What you should do is modify any int that can hold a pointer to intptr_t. You can convert a pointer value to an integer type if you really want to, but it's rarely a good idea, and certainly not necessary if you just want to print its value. unsigned int b=10; Connect and share knowledge within a single location that is structured and easy to search. Is there a higher analog of "category with all same side inverses is a groupoid"? #include If your compiler defines intptr_t or uintptr_t, use those, as they are integer types guaranteed to be large enough to store a pointer. #include The UNIX and Linux Forums - unix commands, linux commands, linux server, linux ubuntu, shell script, linux distros. Package: vlc Version: 0.8.4-svn20050810-1 Severity: serious Hi, Your package is failing to build on 64 bit arches with the following error: g++ -DHAVE_CONFIG_H -I. What is the POINTER_32 macro? If you need to keep the returned address, just keep it as void*. My guess is OP's situation is a void* is being used as general storage for an int, where the void* is larger than the int. So eg: int i = 123; Help us identify new roles for community members, Proposing a Community-Specific Closure Reason for non-English content. Converting a void* to an int is non-portable way that may work or may not! unsigned int c; 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. } #include So reinterpret_cast has casted it to long type and then static_cast safely casts long to int, if you are ready do truncte the data. The rubber protection cover does not pass through the hole in the rim. Is it safe to delete a pointer that was cast from void in C++? Hi guys I see there may be other reasons. Pointer packing. {cout<<"from der\n";} static const int in switch statement from another class cause error C2051: case expression not constant, Explicit cast from int to a user defined class, c++, error while trying to get the int from a string, Calling a Derived Class method from a Void Pointer cast to a Base Object. Making statements based on opinion; back them up with references or personal experience. Man Pages, All
Here c returns some junk value. Casting a pointer to an int is horrible from a portability perspective. The size of int is defined by the mix of compiler and architecture. This is 5() About size_t and ptrdiff_t. Linux Man Pages, Help with understanding ( int, char, long, short, signed, unsigned etc. ), C++ program is crashing on re-assigning const static member variable using an int pointer, Handle int listen(int sockfd, int backlog) in TCP. This is how you would do it: Thanks for contributing an answer to Stack Overflow! }. To solve this in line 5 instead of (int)pLocation3 we have to use (int64_t)pLocation3 as a 64bit machine compitable. The correct answer is, if one does not mind losing data precision. d->disp(); cast from const void* to unsigned int loses precision. cannot convert argument 1 from int to int && error. That could create all kinds of trouble. from the manual How do I dynamically cast from a void * pointer generically? It has a parameter called backlog and it limits the maximum length of queue of pending list. ric. 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. main() There is an option to let the "Fatal behavior" might not be noticeable until you've already used 4 GB of memory. This will get you a pointer from a 32 bit offset: A function pointer is incompatible to void* (and any other non function pointer). Keep in mind that thrArg should exist till the myFcn() uses it. Add a new light switch in line with another switch? You do not want to suppress these errors because most likely, they are indicating a problem with the code logic. Explanation . A typedef might make this a little nicer in the code. Your code is broken. #include Do non-Segwit nodes reject Segwit transactions with invalid signature? There is no "correct" way to store a 64-bit pointer in an 32-bit integer. How can I remove a key from a Python dictionary? To learn more, see our tips on writing great answers. If the function had the correct signature you would not need to cast it explicitly. Casting a pointer to void* and back is valid use of reinterpret_cast<>. pthread passes the argument as a void*. The types uintptr_t and intptr_t, defined in or , are guaranteed to be able to hold a converted void* pointer value without loss of information (and will not be defined if no integer type qualifies). }; void disp() The rubber protection cover does not pass through the hole in the rim. Then in such case, user can use void pointers to store any object. It is a valid use case to cast things from void* to integer types if you have a generic function that takes (void *) because the a user can pass their own Is it correct to say "The glue on the back of the sticker is dying down so I can not stick the sticker to the wall"? char d1; int x = (int)arg; use: int x = (long)arg; On most platforms pointers and longs are the same size, but ints and pointers often are not the same size on 64bit platforms. When I declare a variable "unsigned;" what did I do it??? . Partitioning/batch/chunk a container into equal sized pieces using std algorithms. Before invalidating anything, please always consider the requirement first. #include int b1; int main() { https://www.cnblogs.com/wajika/p/6516379.html, : } I personally upvoted this answer because by it's first line of text it helped me to understand the reason of this strange error message and what am I, poor idiot, doing :D. Not valid on Windows 64 - long is still 32-bit but pointers are 64-bit. Consider the case if user has to make a generic array (in C where there is no template). The point is (probably) that the value passed to the thread is an integer value, not really a 'void *'. # I have used Login or Register to Ask a Question and Join Our Community, All UNIX
# Unsign to sign public: How many transistors at minimum do you need to build a general-purpose computer? C99 standard library provides intptr_t and uintptr_t typedefs, which are supposed to be used whenever the need to perform such a cast comes about. , 1.1:1 2.VIPC, error: cast from void* to int loses precision. 5() Would salt mines, lakes or flats be reasonably found in high, snowy elevations? To learn more, see our tips on writing great answers. while true Andrey Karpov. fileDescriptor = Hi, You have to manually edit those files in order to replace them with code that isn't likely to be buggy and nonportable. Half your pointer will be garbage. or do I have to manually edit these files to avoid these casts? If not, check the pointer size on your platform, define these typedefs accordingly yourself and use them. When you move to 64bit, you can no longer store a pointer in an int - it isn't large enough to hold a 64bit pointer. We do not currently allow content pasted from ChatGPT on Stack Overflow; read our policy here. Get the address of a callback function to call dynamically in C++, error: call of overloaded function ambiguous, error: cast from to unsigned int loses precision [-fpermissive]. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Please help me with the following code to get the difference in values. I would like to say that there may be some cases where this is required. base *b=new derv; int* pi = const_cast(&CA::i); Should this static cast from int to double be avoided? We are migrating our c-code to 10.2.0.3.0. C++ error: cast from int* to int loses precision. How many transistors at minimum do you need to build a general-purpose computer? Expressing the frequency response in a more 'compact' form. It's an error for a reason: int is only half as big as void* on your machine, so you can't just store a void* in an int. That's perfectly fine. do Use #include to define it. tell me. You could use this code, and it would do the same thing as casting ptr to (char*) returnPtr [j] = # Unsign to sign This is an old C callback mechanism so you can't change that. The 32 remaining bits stored inside int are insufficient to reconstruct a pointer to the thread function. I faced similar problem. int* pi = const_cast(&CA::i); How can i get the What does the warning message 724 "Cast converts default int return type to." This allows you to reinterpret the void * as an int. If your standard library (even if it is not C99) happens to provide these types - use them. Thanks for contributing an answer to Stack Overflow! Easiest way to convert int to string in C++. You can use a 64 bits integer instead howerver I usually use a function with the right prototype and I cast the function type : They're not god's law engraved in stone, and treating like they are isn't helping. Because the system I compiled is linux64-bit, the pointer type and the long type are equal in size (8B) and the int type is 4B, so there will be: lost precision. The problem has nothing to do with your Makefile; it's an error in your C++ source code. Off-topic: Prefer English variable names. const static int i; cast from const void* to unsigned int loses precision. rev2022.12.9.43105. Sorry, I had overlooked your previous reply to my comment. I agree passing a dynamically allocated pointer is fine (and I think the best way). Subtract key from that and you get a number corresponding to the address of Ready to optimize your JavaScript with Rust? Suppressing the warnings are a bad idea, but there may be a compiler flag to use 64-bit ints, depending on your compiler and architecture, and this is a safe way to fix the problem (assuming of course that the code didn't also assume ints are 32-bit). You can try to use intptr_t for best portability instead of int where pointer casts are required, such as callbacks. If the original type is a void *, converting to an int may lose date on platforms where sizeof(void *) != sizeof(int) (which is true of LP64 programming model). char d1; This means you. You guys are all missing the point. int b1; How can I randomly select an item from a list? Is this an at-all realistic configuration for a DHC-2 Beaver? And you can't pass a pointer to a stack based object from the other thread as it may no longer be valid. Sometimes it is sensible to want to split up a 64-bit item into 2 32-bit items. As Ferruccio said, int must be replaced with intptr_t to make the program meaningful. Is it appropriate to ignore emails from a student asking obvious questions? # sign.sh What is the difference between const int*, const int * const, and int const *? Bug#334109: aptsh: FTBFS (amd64): cast from 'void*' to 'int' loses precision. On your platform, a pointer does not fit in an int. You can't just cast a string to a numeric type - C just doesn't work that way. I have a function with prototype void* myFcn(void* arg) which is used as the starting point for a pthread. main() The code needs to be changed and reviewed for 64bit compatibility. Is it illegal to use resources in a University lab to prove a concept could work (to ultimately use to create a startup). Perhaps you need to read up more on pointers and how they work? If you really want to fool the compiler, the following technique seems to work, even with -Wall: Here it takes the address of v, converts the address to a pointer of the datatype you want, then follows the pointer. cout << CA::i << endl; C++ how to get the address stored in a void pointer? void* myFcn(void* arg) { int * data = reinterpret_cast (arg); int x = *data; delete data; :sbiOP. { Remembering to delete the pointer after use so that we don't leak. 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. 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. int main(){ I would create a structure and pass that as void* to pthread_create. Instead of using a long cast, you should cast to size_t. public: It's an int type guaranteed to be big enough to contain a pointer. }. Why cast a float to an integer? Test.c:93:25: warning: implicit conversion loses integer precision: 'int' to 'unsigned char' [-Wconversion] WriteNibble ( command<<4 ); //then the low nibble. return(0); What is the difference between int** func() and int*& func(). void disp() "No appropriate default constructor available"--Why is the default constructor even called? When I declare a variable "unsigned;" what did I do it??? You would loose half of the pointer and when the program later tries to get the pointer out of that int again, it won't get anything useful. The bug is in the source, on the line shown by the error. @jogojapan: You are right. Does balls to the wall mean full speed ahead or full speed ahead and nosedive? If I have three hello everybody! int c1; To learn more, see our tips on writing great answers. If the reason for the cast is to make the pointer opaque, then void* already achieves this, so the code could use void* instead of int. ), For those who are interested. A WORD is 16 bits, and a size_t is usually 32 or 64 bits depending on the compiler options, the same size as a pointer with the same options. Is there any reason on passenger airliners not to have a physical lock between throttles? This method will not work on 64 bit Big Endian platform, so it unnecessarily breaks portability. from the manual is int64_t or u_int64_t what I need ? Is it safe to cast an int to void pointer and back to int again? Therefore, you need to change it to long long instead of long in windows for 64 bits. Find centralized, trusted content and collaborate around the technologies you use most. I don't know what TThread::Printf is, it's not standard. Don't pass your int as a void*, pass a int* to your int, so you can cast the void* to an int* and copy the dereferenced pointer to your int. It has a parameter called backlog and it limits the maximum length of queue of pending list. For a 64bit machine, it's tricky to cast an int pointer(hex format) to int value or char pointer to int value because each block of memory for an int variable is 32 bit and for char it's 8 bit. However, at the same time, to treat it as an array of integers, user can also store integers in the array. BUT converting a pointer to void* and back again is well supported (everywhere). Hello everey one, here i am attempting to compile a c++ project .it's throughing the following errors. testhandlerint4, 6484int8handler84int, 64long8intlong, bandaoyu: { Compile error: cast from void* to int loses precision [-fpermissive] While compiling the current HEAD (17b63fda) on Linux, I receive an error while compiling wx-podule { Change jdk path in IntelliJ 13 when compiling from 32 bit program file folder to 64 bit one, Ignore [clang-diagnostic-error] clang-tidy caused by 3rd party headers, c++: cast from "const variable*" to "uint32" loses precision. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. Handle int listen(int sockfd, int backlog) in TCP, C++ program is crashing on re-assigning const static member variable using an int pointer, Help with understanding ( int, char, long, short, signed, unsigned etc. ). Does the collective noun "parliament of owls" originate in "parliament of fowls"? I want to create a file with permissions for read, write, and execute to everybody using C, so I write this code: I can't imagine many cases where that is the correct thing to do, or where it won't cause errors. fix cast from void* to Gluint 8a04369 gcc complained OsvrRenderingPlugin.cpp:788:44: error: cast from 'void*' to 'GLuint {aka unsigned int}' loses precision [-fpermissive] Fundamentally, treating the bits of a pointer as if they were an integer is not a portable thing to do (although it can be made to work on many platforms). It seems you have a definition of size_t that is incorrect, you should fix it. Add a new light switch in line with another switch? If your code has the chance to ever be ported to some platform where this doesn't hold, this won't work. { Is it safe to cast to int from std::round? derv *d; @Martin York: No, it doesn't depend on endiannness. https://bbs.csdn.net/topics/603958740 { He's down-casting, this is commonly used when you need to pass either a bunch of data via a pointer, or just an integer argument. Most answers just try to extract 32 useless bits out of the argument. public: As was pointed out by Martin, this presumes that sizeof(void*)>=sizeof(int). No idea how it amassed 27 upvotes?! void If I set backlog to 128, is it means no more than 128 packets can be handled by server? Making statements based on opinion; back them up with references or personal experience. Thanks Jonathan, I was thinking about my answer in another thread: AraK is correct, passing integers a pointers are not necessarily interchangeable. Examples of frauds discovered because someone tried to mimic a random sequence. Is there a compiler flag to suppress these errors? my machine details if, so how can I printf it to stdout? If you cast a pointer to an integer, you should probably use intptr_t or uintptr_t from stdint.h which are guaranteed to be big enough. c = b - (unsigned int )sizeof(a); Not the answer you're looking for? class derv : public base When that user data then gets passed back to the specific code making use of it, it can cast it back to an integer. int main() Do bracers of armor stack with magic armor enhancements and special abilities? Would it be possible, given current technology, ten years, and an infinite amount of money, to construct a 7,000 foot (2200 meter) aircraft carrier? This is not a conversion at all. d=dynamic_cast(b); Can any one tell me why my following program is crashing? Thanks, Ready to optimize your JavaScript with Rust? If he had met some scary fish, he would immediately return to the surface. virtual void disp() @jogojapan: There are few valid cases where this is requirement. Well it does this because you are converting a 64 bits pointer to an 32 bits integer so you loose information. #include Do bracers of armor stack with magic armor enhancements and special abilities? I converted this problem from typecasting a pointer to long You need to pass an actual pointer. Penrose diagram of hypothetical astrophysical white hole. Thus as a result it may be less error prone to generate a pointer dynamcially and use that. Is it illegal to use resources in a University lab to prove a concept could work (to ultimately use to create a startup). So eg: I'm not going to weigh in on whether it's right or wrong to abuse a void* this way. I am new to C. (used it some in college). If you convert ( void*) to ( long) no precision is lost, then by assigning the ( long) to an ( int ), it properly What you're actually casting is the address in memory that the string resides at.. Help us identify new roles for community members, Proposing a Community-Specific Closure Reason for non-English content, Why is cast from X* to Y loses precision a hard error and what is suitable fix for legacy code, error: cast from 'void*' to 'int' loses precision, Missing include "bits/c++config.h" when cross compiling 64 bit program on 32 bit in Ubuntu. You'll risk losing some of the true value of the float unless its value is small enough to fit inside that integer. cout << CA::i << endl; Japanese girlfriend visiting me in Canada - questions at border control? struct a{ How to get the error message from the error code returned by GetLastError()? hi, Sorry I meant storing objects with different types void* allows reusing the same pointer for multiple object types.. But the I want to compile this example program in order to embed Python in C ++. Site design / logo 2022 Stack Exchange Inc; user contributions licensed under CC BY-SA. So you know you can cast it back like this. Thanks for contributing an answer to Stack Overflow! Did neanderthals need vitamin C from the diet? Can any one tell me why my following program is crashing? char *ptr; //
const static int i; Can you please explain it with suitable example. Hello everey one, here i am attempting to compile a c++ project .it's throughing the following errors. struct a{ But I have a suggestion to bypass the compiler. const int CA::i = 10; I want to create a file with permissions for read, write, and execute to everybody using C, so I write this code: How did muzzle-loaded rifled artillery solve the problems of the hand-held rifle? Thanks, I am new to C. (used it some in college). This is why the stdint.h header was created, to allow you to explicitly state the size of the type you're using across many different platforms with many different word sizes. You'd be better off casting to a uintptr_t or intptr_t (from stdint.h, and choose the one that best matches the signedness you need). int main(){ class CA { Wrong. This is flat out wrong. Last Activity: 1 September 2009, 9:07 AM EDT. Half your data will get thrown away. C++ typecast: cast a pointer from void pointer to class pointer; srand (time (null)) causes compiler warning: implicit conversion loses integer precision; Why does Visual C++ warn on implicit cast from const void ** to void * in C, but not in C++? I don't see how anything bad can happen . *pi = 9; What I am saying is that you shouldn't convert 64-bit pointers to 32-bit integers. We are migrating our c-code to 10.2.0.3.0. { How to cast an int unique_ptr into a void unique_ptr? If the reason for the cast is to achieve compatibility with some existing library (perhaps an older callback interface) which cannot be modified, then I think you need to review the documentation for that library. Received a 'behavior reminder' from manager. b->disp(); Multiplatform way to write a std::wstring into a file in C++, Forwarding references: reference parameter origin. https://bbs.csdn.net/topics/603958740 Since 32 and 64 are both greater than 16, the compiler is complaining and rightly so. Is for saving RAM), use union, and make sure, if the mem address is treated as an int only if you know it was last set as an int. virtual void disp() Why does the USA not have a constitutional court? The programs compiled clean. I understood, but that would introduce dynamic memory and ugly lifetime issues (an object allocated by one thread must be freed by some other) - all just to pass an. Rvalue Reference is Treated as an Lvalue? You are casting a pointer to an integer, why would you think that is a good idea in this case? How should I handle cast from void* to int loses precision when compiling 32-bit code on 64-bit machine? 64-bit lessons. Like it or not, English is the predominant language for programming and you make live easier for any non-hispanophone We do not currently allow content pasted from ChatGPT on Stack Overflow; read our policy here. To respond: What I am saying is not that you shouldn't convert pointers to integers. On 32-bit systems, ints and pointers are both four bytes, so the cast works even though it is bad form. #include Knowledge Base. int fileDescriptor; testhandlerint46484int8handler84int64l :
For gcc, the flag is -m64. What you do here is undefined behavior, and undefined behavior of very practical sort. This is memory reinterpretation - a completely unacceptable way to do what the OP is trying to do. If those types are not available, size_t or ptrdiff_t are also large enough to hold a pointer on most (not all) platforms. What is the maximum size of the map object in c++ and java? error: cast from void* to int loses precision. You do not want to suppress these errors because most likely, they are indicating a problem with the code logic. If you suppresses the errors, this So, solution #3 works just fine. Something can be done or not a fit? error: cast from void* to int loses precision. Ready to optimize your JavaScript with Rust? error: cast from 'void*' to 'int' loses precision. Copyright 2022 www.appsloveworld.com. 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. Find centralized, trusted content and collaborate around the technologies you use most. const int CA::i = 10; That will definitely cause the loss of information. I type this to compile: Size of pointer may be greater than size of int and depends of memory model. 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Inside int are insufficient to reconstruct a pointer to the curvature of spacetime use # include cstdint... The point is ( probably ) that the value passed to the thread is an integer ( int ) (... ; C++ how to get the error message from the manual is int64_t or u_int64_t what I need to '. Platform that the value passed to the wall mean full speed ahead and nosedive lakes or be. Really a 'void * ' the starting point for a DHC-2 Beaver void pointer back. Energy `` equal '' to the surface snowy elevations man Pages, all here C returns some junk value salt! To 'int ' loses precision - ( unsigned int cast from void* to int loses precision not even remotely `` the correct answer.. Portability perspective virtual void disp ( ) { I would create a structure and that..., on the line with another switch cstdint > to define it Python is not big to.