How would you write this type of function so as not to generate "assignment discards qualifiers" warnings? This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.mirroring instructions on how to clone and mirror all data and code used by this external index. This breaks the contract of the function parameter declaration, which "promises" not to modify the object to which pt_Param pointer. And hence the warning. rev2022.12.11.43106. How do I put three reasons together in a sentence? G_DEFINE_TYPE is currently used 4 times in our code. But why? Declare the target variable also as const: Thanks for contributing an answer to Stack Overflow! Don't tell someone to read the manual. The parameter for the function is a pointer to a constant, const LIST *head; this means you cannot change what it is pointing to. Help us identify new roles for community members, Proposing a Community-Specific Closure Reason for non-English content, C (Linux): warning: assignment discards qualifiers from pointer target type, Passing Argument 1 discards qualifiers from pointer target type, Warning while sorting a 2D array with qsort, warning: assignment discards qualifiers from pointer target type, C function returns const pointer that is assigned to nonconst pointer - warning not error, Sending "char**" into "const char**" function parameter, C: Compiler warning "return discards qualifiers from pointer target type". Re: C - strtok discards qualifiers from pointer target type Assigning directly to the return of strchr() is going to bite you hard with a segfault when program_cmd doesn't contain a space. The part that's wrong is trying to convert a "pointer to a const pointer" into a "pointer to a pointer to const"; you're removing the const from what the pointer points to ("discarding the qualifier"). In glibc 2.15's strstr() source code: you should probably change the return value to, The prototype is exactly the same as standard C's strstr() source code which throws tons of. The prototype is exactly the same as standard C's strstr(). @sheu did a solid job of catching it about 24 hours before I really thought about it long enough to realize he was right all along (and I actually upvoted that answer before writing this one). Why does C in contrast to C++ ban adding const-qualification to both levels of a pointer-to-pointer? c++discards qualifiers. You are casting a const char * (let's call it non-modifiable string) to a char * (modifiable string) you discard the const qualifier. Why is there a warning for casting from char** to void**, but not from char* to void*? Output: 'const' qualifiers cannot be applied to 'int&'. No. Dumb question, but what does a const return type look like? Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, Just FYI I've had gcc print unidentified warnings like this that I think are controlled by. -Wcast-qual outputs this warning on stristr()'s return line. warnings your are getting from your compiler are misleading and formally. From above we know that char ** and const char ** (aka. Briefly, consider this example closely related to yours: If you assign some const pointer to a void pointer without an explicit cast gcc does not complain about the complete loss of type, but it does warn about losing constness. Load an array of const char* values from your char* values and pass that instead. When compiling in C++, you'll just plain error because the parameter signature doesn't match. Connect and share knowledge within a single location that is structured and easy to search. If you turn on -Wunused you'll see a warning about int size in find_largest. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Error: passing x as 'this' argument of x discards qualifiers. Why would Henry want to close the breach? This cast discards qualifiers from pointer target type. MarioG-X changed the title Make warnings in expat look serious Make in expat: passing 'const char **' to parameter of type 'char **' discards qualifiers in nested pointer types Jan 9, 2021 Copy link const causing incompatible pointer type. opposed to 'const char*' pointer) with a string literal, it still does not. Consider a type like "const char * volatile * const * restrict * const" -- the diagnostic would have to point out which qualifiers are discarded, and it could be that restrict and volatile are discarded but the consts are fine. Sign in. . 6. In the United States, must state courts follow rulings by federal courts of appeals? Thanks again. Thanks for contributing an answer to Stack Overflow! Any thoughts? blob: 2d755ae42f3dd98699e3fb90d0232dcf4f24ee9d [] [] [] +1 (416) 849-8900, If there is an error incoming, exit and propagate to the next. If a question is poorly phrased then either ask for clarification, ignore it, or. @ 2018-10-01 21:34 Christophe Lyon 2018-10-02 1:04 ` Craig Howland 2018-10-02 12:40 ` Richard Earnshaw (lists) 0 siblings, 2 replies; 15+ messages in thread From: Christophe Lyon @ 2018-10-01 21:34 UTC (permalink / raw) To: newlib [-- Attachment #1: Type: text/plain, Size . How can you know the sky Rose saw when the Titanic sunk? Compiler warning: Passing 'const option' as this discards qualifiers. / clang / test / Sema / pointer-conversion.c This might be because you were changing your code and forgot to change that part, but just thought I'd point it out since it might lead to bugs later on. Asking for help, clarification, or responding to other answers. private: int age; We do not currently allow content pasted from ChatGPT on Stack Overflow; read our policy here. You are receiving this mail as a port that you maintain is failing to build on the FreeBSD package build server. @ChrisK Thanks, Chris. Edit: I didn't leave it out. If you believe this to be in error, please contact us at [email protected]. I still don't think this is right. Remember, by the standard const goes to the item immediately to its left. class person {. Find centralized, trusted content and collaborate around the technologies you use most. Is this an at-all realistic configuration for a DHC-2 Beaver? (or change the callee prototype, but thats cheating =P). I just can't seem to resolve this warning! Find centralized, trusted content and collaborate around the technologies you use most. Connect and share knowledge within a single location that is structured and easy to search. How do I store a pointer (node) returned by a function to my main? When it appears to the right of anything it applies to the immediate-left decl-part, be it a data type part or a pointer part, but no matter what it only applies to a single part. hongyd 2018-02-27 14:20:17 13961 2. 20 Bay Street, 11th Floor Toronto, Ontario, Canada M5J 2N8 How to check if widget is visible using FlutterDriver. You can delete you answer if it's not relevant. Though it originated as a re-engineering of C++, D is a profoundly different language features of D can be considered streamlined and expanded-upon ideas from C++, however D also draws . Why can't I convert 'char**' to a 'const char* const*' in C? Could you provide the function prototype you are using? whenComplete() method not working as expected - Flutter Async, iOS app crashes when opening image gallery using image_picker. A constant pointer is passed to "delete()", but you try to assign it to a non-constant one. Declaring it on the most-left of a data type is a nicety that the language supports, but often introduces confusion or problems. My answer is completely irrelevant! You don't have one in your function, so you could consider changing the argument type if you reallyneed a non-constreturn type. Is MethodChannel buffering messages until the other side is "connected"? The solution is either to change the return type of the function, or to find a non-const charto point at. In following function, would get the warning that you encountered with. I don't really know if this is the best way but at least I don't get more. Sure. Unless you use -Wno-incompatible-pointer-types-discards-qualifiers in which case it will compile, run, and segfault (if your system is sane). You really should check the return and only dereference/reassign once you know that it's not NULL. The -Wdiscarded-qualifiers and -Wincompatible-pointer-types warnings (and possibly others like these two) point out incompatibilities in expressions involving conversions between incompatible pointer types but neglect to mention the actual types of the pointer operands or where they are declared. It seems odd, but VS is actually more correct (wonders never cease). c Are defenders behind an arrow slit attackable? Chances are they have and don't get it. Does every positive, decreasing, real sequence whose series converges have a corresponding convex sequence greater than it whose series converges? Understand that English isn't everyone's first language so be lenient of bad 1 comment Collaborator llvmbot commented on May 22, 2015 Contributor Weverything commented on Nov 26, 2021 llvmbot transferred this issue from llvm/llvm-bugzilla-archive on Dec 9, 2021 You don't have one in your function, so you could consider changing the argument type if you really need a non-const return type. . BR Magnus Reftel 2014-03-11 Manuel Lpez-Ibez <[email protected]> PR c/55383 * c/c-typeck.c: use correct format string in cast-qual warning [-- Attachment #2: bug55383.patch --] [-- Type: text/x-patch, Size: 1520 bytes --] diff --git a/gcc/c/c-typeck.c b/gcc/c/c-typeck.c index 524a59f..0bfc12b 100644 --- a/gcc/c/c-typeck.c +++ b/gcc/c/c . This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL). char const **), are not the same. Compiler Warnings with memcpy () and pointer types. Using flutter mobile packages in flutter web. clang will compile it with a warning in C, but allow it (which I found surprising). Sign in. And __atomic_load supports pointers to pointers that have qualifiers on the inner type. How do the likely/unlikely macros in the Linux kernel work and what is their benefit? Add a Solution 1 solution Solution 1 You only have a const void* and assign that to a void*. I can do it, however, I need to find a way of getting them to show up first, as when I enabled -Wdiscarded-qualifiers locally last week, they weren't appearing. warning: cast discards qualifiers from pointer target type. Then I thought he was wrong about the same time he thought his answer wasn't applicable. Note C and C++ deals with inner qualifiers differently. Does integrating PDOS give total charge of a system? Object type cannot be converted to target type. The Standard claims in 6.5.16.1 for an assignment, that " both operands are pointers to qualified or unqualified versions of compatible types, and the type pointed to by the left has all the qualifiers of the type pointed to by the right " The last part of the sentence means that adding a qualifier to the pointed-to type is no problem. Maarten ^ permalink raw reply [flat|nested] 7+ messages in thread Ready to optimize your JavaScript with Rust? 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? How can I make a function with optional arguments in C? Netdev Archive on lore.kernel.org help / color / mirror / Atom feed * [PATCH] batman-adv: remove unnecessary type castings @ 2022-04-21 15:48 Yu Zhe 2022-04-22 2:20 ` kernel test robot ` (5 more replies) 0 siblings, 6 replies; 11+ messages in thread From: Yu Zhe @ 2022-04-21 15:48 UTC (permalink / raw) To: mareklindner, sw, a, sven, davem, kuba, pabeni Cc: b.a.t.m.a.n, netdev, linux-kernel . D, also known as dlang, is a multi-paradigm system programming language created by Walter Bright at Digital Mars and released in 2001. New Member. You have declared returnvalue as a pointer to a const char, but then you've cast it to a pointer to non-const char. How to get rid of `deprecated conversion from string constant to char*` warnings in GCC. *Re: [PATCH] sh: clk: Fix discarding const qualifier warning 2020-01-07 13:00 ` Geert Uytterhoeven @ 2020-01-07 13:05 ` Krzysztof Kozlowski 2020-01-07 13:32 ` Krzysztof Kozlowski 0 siblings, 1 reply; 6+ messages in thread From: Krzysztof Kozlowski @ 2020-01-07 13:05 UTC (permalink / raw) To: Geert Uytterhoeven Cc: Yoshinori Sato, Rich Felker . 8. incorrect. As a rule-of-thumb, if const appears on the far-left of a decl immediately before the type, it applies to the data type; not the subsequent pointer (if any). As a rule-of-thumb, if const appears on the far-left of a decl immediately before the type, it applies to the data type; not the subsequent pointer (if any). Sign in. Initialization discards qualifiers from pointer target type PolicyException: Required permissions cannot be acquired what does this error mean What does this error message mean ? Hence you can modify the target with pt_SAP->pt_param although you could not with pt_Param. EDIT : One extra cast or a wrapper macro (for the time being) is not something that tedious, especially since this needs to be dealt with in either glib or clang. And hence the warning. VS2010 and VS2012 both, on the other hand, toss an error: error C2440: 'initializing' : cannot convert from 'char **' to 'const char **'. Initialization discards qualifiers from pointer target type c linked-list 96,256 Solution 1 It's this part: LIST *start = head; Copy The parameter for the function is a pointer to a constant, const LIST *head; this means you cannot change what it is pointing to. S4/main_python.c:1701:51: warning: passing 'double *' to parameter of type 'const double *_' discards qualifiers in nested pointer types [-Wincompatible-pointer-types-discards-qualifiers] C'est la vie. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. This was the answer that ultimately made mine work, and if the casual reader hasn't already done so, it certainly deserves a vote. Nestled down in the type declaration is the fact that the first of these does not allow modification to the final data, the second does. Can virent/viret mean "green" in an adjectival sense? And regarding how to fix this warning. Not the answer you're looking for? 1const. literals in C don't have const-qualified . [unhandled content-type:application/gzip] Last update: 2021-10-01 09:27 [W:0.028 / U:10.444 seconds] 2003-2020 Jasper Spaans |hosted at Digital Ocean and TransIP | Read the blog | Advertise on this site How could my characters be tricked into thinking they are on Mars? In the example: Because we are setting a non const sub-pointer to a const pointer. On VS2012 and VS2010 both the marked line will flag an error without a cast. discards qualifiers from pointer I have read a number of threads related to this type of issue on different forums but I'm still not getting it, perhaps someone can enlighten me! Its there, but you're point on the safety would seem accurate. That's why your compiler is complaining. So how does this affect your question? Why does adding an additional const qualifier "discard qualifiers in nested pointer types"? Consider the following code, which essentially does everything you're wishing except invoke a function. How does legislative oversight work in Switzerland when there is technically no "opposition" in parliament? If that were allowed, then: The warning tells you that the function you're calling expects the given parameter as const char** but you're passing a char** parameter. The code needs to figure out which qualifiers are discarded (and those qualifiers may be disjoint in the type specifier). It depends on what you are trying to do. Types III: Conversions Another place is with explicit pointer changes, if you don't want to use an intervening void*, but these are also pretty uncommon: long x = 3490; long * p = & x; unsigned char * c = (unsigned char *) p; A third place it's often required is with the character conversion functions in <ctype.h> where you should cast questionably-signed values to unsigned . BTW, pDst = (unsigned long *) & (pReceiveBuf->Dat1);, compiles OK. This is a fun bit of C, which makes sense if you think hard enough about it. For now, I'm passing the arguments by casting them to const char **. You're passing size, but not using it. All the compiler is saying is: "Hey, you said to the caller 'I won't change anything', but you're opening up opportunities for that.". const. Not the answer you're looking for? Well, think about this. For example, if I need to create a reference to const integer then I can write the expression in two ways. Ready to optimize your JavaScript with Rust? Qsort array | warning: initialization discards qualifiers from pointer target type; warning: "assignment discards 'const' qualifier from pointer target type" typedef function pointer -> initialization from incompatible pointer type; C (gcc) warning: initialization from incompatible pointer type when calling pthread_cleanup_push() initialization . TabBar and TabView without Scaffold and with fixed Widget. what is the second const doing in "const int const &someval"? Disconnect vertical tab connector from PCB. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Is there any other way I can get rid of it? Why do these C struct definitions give warnings and errors? Asking for help, clarification, or responding to other answers. When contacting us, please include the following information in the email: User-Agent: Mozilla/5.0 _Windows NT 6.3; Win64; x64_ AppleWebKit/537.36 _KHTML, like Gecko_ Chrome/103.0.0.0 Safari/537.36, URL: stackoverflow.com/questions/37160873/warning-discards-const-qualifiers-from-pointer-target-type. To learn more, see our tips on writing great answers. What is the problem ? what does -0x4(%rbp) means in gdb disassembly? Turns out we were both wrong on that leap, because he was right the first time, I was wrong the second time, and now ugh. Making statements based on opinion; back them up with references or personal experience. 4. type qualifier at the pointer conversion. Solution 2 To assign to the same type, you want. It's also worth bearing in mind that the libraries are usually written by the compiler authors, so they're free to make all sorts of kludges that would otherwise be questionable/implementation-defined/undefined. - sqlite3_exec - Failed to set synchronous mode = 1 (Normal) What does it mean SELECT EXISTS (SELECT 1 FROM favoritelist WHERE id=:id) The syntax for declaring a const qualifier is: const data-type constant-name = value; Or data-type const constant-name = value; Use the const type qualifier to qualify an object whose value cannot be changed at any given time. Do you need your, CodeProject, * Cast "const char *" pointers to "char *" to avoid compiler warnings. Does a 120cc engine burn 120cc of fuel a minute? Why does passing char** as const char** generate a warning? This patch fixes the warnings "passing argument 1 of '__memcpy' discards. How to change background color of Stepper widget to transparent color? I suspect that qualifying a return value is a GNUism and am not sure if there is a preferred method that avoids this blob . Making statements based on opinion; back them up with references or personal experience. The warning is because char ** and const char ** are not equivalent (duh). To be correct, you could fix the prototype (callee), or fix the caller (by loading an array of const char * and passing that). Why does my stock Samsung Galaxy phone/tablet lack some features compared to other Samsung Galaxy models? Is the EU Border Guard Agency able to tell Russian passports issued in Ukraine or Georgia from the legitimate ones? android / platform / external / clang / 163ada8 / . CGAC2022 Day 10: Help Santa sort presents! assignment from incompatible pointer type in c, for a pointer to struct; Getting warning of passing argument 3 of 'pthread_create' from incompatible pointer type [-Wincompatible-pointer-types] warning: "assignment discards 'const' qualifier from pointer target type" Assignment from incompatible pointer type when using Linked Lists discards qualifiers. In C++ you can write reference to const in two ways. I'm trying to print the list of a singly linked list that I referred to in link text. "I'm making things more const! @codesourcery.com cc: When should i use streams vs just accessing the cloud firestore once in flutter? spelling and grammar. Site design / logo 2022 Stack Exchange Inc; user contributions licensed under CC BY-SA. qualifiers from pointer target type" and "passing argument 2 of '__memcpy'. @NigelRidley: Well, there's no one standard C implementation, but I imagine the core of most C libraries were implemented well before language standardisation had occurred. edit: I even answered the wrong question. 106 Chapter 15. c++ discards qualifiers. The solution is either to change the return type of the function, or to find a non-const char to point at. Why do quantum objects slow down when volume increases? Great explanation! I'll try and update the answer to reflect that addition. We do not currently allow content pasted from ChatGPT on Stack Overflow; read our policy here. The content must be between 30 and 50000 characters. Hence you can modify the target with pt_SAP->pt_param although you could not with pt_Param. / test / Sema / pointer-conversion.c. discards qualifiers from pointer target type" when compiling some files. Contribute to microsoft/clang development by creating an account on GitHub. fractional *ADC16Ptr; // pointer for ADC buffers. rev2022.12.11.43106. This IP address (162.241.74.2) has performed an unusually high number of requests and has been temporarily rate limited. Note that these warnings disappear if I prototype the function as const char * err_sng(int err_nbr); Is that legal? And that makes perfect sense. This is obviously a good thing!". When compiling that code in C, without a cast you'll get a compiler warning (or error if compiling with -Werror). warning: discards 'const' qualifiers from pointer target type, Error: binding to reference of type discards qualifiers, Copy "pointer to const" to "pointer to non const" via memcpy, Is there anyway to give this value to my node, Central limit theorem replacing radical n with n. Does a 120cc engine burn 120cc of fuel a minute? Ignore me please. Tigger99. @nondot.org reporter: jonat. Can you safely typecast char ** to const char**? confusion between a half wave and a centre tapped full wave rectifier. Cannot convert from 'char **' to 'char *[]'. Given, you do have to really step out of your happy place to break it, but it is still none-the-less broken. In general I'd say: make up your mind; either warn about both or don't warn about either. Love it when it gets explained in natural language, as if the compiler could talk. recipe for target 'all' failed on Ubuntu 15.10 64-bit. Because these have no direct equivalence: When compiling with clang, the exact warning in C is given as: main.c:15:9: Passing char ** to parameter of type const char ** discards qualifiers in nested pointer types. Is this an at-all realistic configuration for a DHC-2 Beaver? The objects qualified by the ' const' keyword cannot be modified, i.e., an object declared as a 'const' cannot . By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. return discards qualifiers from pointer target type - C / C++ 471,518 Members | 887 Online Sign in Join Post + Home Posts Topics Members FAQ home > topics > c / c++ > questions > return discards qualifiers from pointer target type Join Bytes to post your question to a community of 471,518 software developers and data experts. When it appears to the right of anything it applies to the immediate-left decl-part, be it a data type part or a pointer part, but no matter what it only applies to a single part. IntelliSense: the object has type qualifiers that are not compatible with the member function. You've discarded the constqualifier, so the compiler complains that you've discarded it! Improve INSERT-per-second performance of SQLite. Sign in. const void* const* fields = SS_Values1; #2. Site design / logo 2022 Stack Exchange Inc; user contributions licensed under CC BY-SA. fuchsia / third_party / llvm-project / 1042f079ee658df896766bbbb84126501aa56221 / . edit 2: after the gentleman question asker clarifies his question, it turns out that my answer is in fact relevant. Why would Henry want to close the breach? email is in use. bug id: 23642 summary: -wincompatible-pointer-types-discards-qualifiers should note the particular discarded qualifiers product: clang version: trunk hardware: pc os: all status: new severity: enhancement priority: p component: -new bugs assignee: unassignedclangb. At the bottom of one is a pointer to a const char, while the other has a pointer to char. blob: 2d755ae42f3dd98699e3fb90d0232dcf4f24ee9d [] [] [] How to tell GCC to generate 16-bit code for real mode, error: conflicting types for built-in function tolower [-Werror], Simple makefile for compiling a shared object library file, Creating a shared library from a static library using GNU toolchain (gcc/ld), _T( ) macro changes for UNICODE character data. You've discarded the const qualifier, so the compiler complains that you've discarded it! You are receiving this mail as a port that you maintain is failing to build on the FreeBSD package build server. % gcc -c func1.c -Wall func1.c:7:12: warning: passing 'const char **' to parameter of type 'char **' discards qualifiers in nested pointer types [-Wincompatible-pointer-types-discards-qualifiers] function2(p); ^ ./func2.h:3:33: note: passing argument to parameter 'p' here extern int function2(char **p . By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. It works, but I do get the compiler warnings: Initialization discards qualifiers from pointer target type, return discards qualifiers from pointer target type. reinterpret_cast casts away qualifiers. How would you create a standalone widget from this widget tree? However, the pointer above is to non-const; you could dereference it and change it. 1. const int& rData = data; 2. int const &rData = data; Note: Reference to . Hence the questionable code if you look to deep! However, the pointer above is to non-const; you could dereference it and change it. c_const. Can you get rid of it another way? Why does the C preprocessor interpret the word "linux" as the constant "1"? The reason why I said it does not discard here is because take: __atomic_load (&p, &q, 0); This is basically p = q; so you need to add const qualifier to the inner most type. It takes awhile to really stare at this, and admittedly I didn't see it at first either. This breaks the contract of the function parameter declaration, which "promises" not to modify the object to which pt_Param pointer. return discards qualifiers from pointer target type (on return statement) in this code: /* Prints singly linked list and returns head pointer */ LIST *PrintList (const LIST *head) { LIST *start = head; for (; start != NULL; start = start->next) printf ("%15s %d ea\n", head->str, head->count); return head; } I am using XCode. The marked line demonstrates the equivalent point-of-cast. 7. At what point in the prequels is it revealed that Palpatine is Darth Sidious? You only have a const void* and assign that to a void*. Instead, you're using the constant SIZE. I know there is a pointer problem, as there is no "->", but how to write code for the compiler not to report the problem? To subscribe to this RSS feed, copy and paste this URL into your RSS reader. I tried searching on the web, and I can't seem to find one. Andrei Alexandrescu joined the design and development effort in 2007. To get rid of this warning you could. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. The reason why const can only be added one level deep is subtle, and is explained by Question 11.10 in the comp.lang.c FAQ. Help us identify new roles for community members, Proposing a Community-Specific Closure Reason for non-English content, const char * vs. const char ** function argument. i2c_arm bus initialization and device-tree overlay. Is it cheating if the proctor gives a student the answer key by mistake and the student doesn't report it? After rereading what I wrote now over three-months past I can't believe I left that out (and yet I included the last example, which is differs by making the base pointer const, duh). Returning a pointer to a constant warning. The rest of this is a diatribe on identifying pointer types, their constness, and what is equivalent to what. Why, you might ask? cast unsigned char * (uint8_t *) to const char *, GCC compiler and converting const char* to char *. As a third option I would better change the function prototype to. Why do some airports shuffle connecting passengers through security again, Disconnect vertical tab connector from PCB, change the function prototype so that the function expects a. / test / Sema / pointer-conversion.c. 5. While it is not a good idea to initialize a 'char*' pointer (as. Please investigate the failure and submit a PR to fix build. Why does the distance from light to subject affect exposure (inverse square law) while from subject to lens does not? android / toolchain / clang / 6ee7c11a698c886d479cfcde70d19004ff366dea / . How can one print a size_t variable portably using the printf family? Compiler returns: warning: cast discards qualifiers from pointer target type. Most programmers like the first expression. If this where: would be correct and it wouldn't let you assign to the const char c. I don't think the compiler should stop you from making something more const. Pedantic gcc warning: type qualifiers on function return type. discard any qualifiers, as the warning message seems to suggest, since string. Would salt mines, lakes or flats be reasonably found in high, snowy elevations? +1 (a long time ago,but its worth mentioning). To learn more, see our tips on writing great answers. How can you know the sky Rose saw when the Titanic sunk? Please investigate the failure and submit a PR to fix build. But can you safely typecast the first to the second? Here is the warning that I'm getting: passing argument 1 of 'atoi' discards qualifiers from pointer target type chromium / external / github.com / llvm-mirror / clang / master / . Why only for double pointers? the problem ( warning: assignment discards qualifiers from pointer target type ) appears in this part of the code: ADC16Ptr = &ADCBUF0; // initialize ADC pointer (will use this later) I assumed fractional was the type that i wanted since I configured the ADC to output this format. Provide an answer or move on to the next question. For second warning: assignment discards 'const' qualifiers from pointer target type 's2ptr' is of type char * and 's2' is of type const char * You are not allowed to assign a const char* value to a char * pointer. (Not safely anyway), and the reason is far more subtle than you may think. Are the S&P 500 and Dow Jones Industrial Average securities? / test / Sema / pointer-conversion.c. Consider the following code, which `` promises '' not to modify the target with pt_SAP- & ;! The standard const goes to the second is still discards qualifiers in nested pointer types broken is there any other way can... An array of const char * * n't see it at first either when compiling in C++, you to. The object to which pt_Param pointer you agree to our terms of service, privacy policy and cookie.... Have and do n't get it technologists worldwide use -Wno-incompatible-pointer-types-discards-qualifiers in which case it will compile with! I put three reasons together in a sentence avoids this blob gives a student the answer to Stack Overflow read... That code in C above we know that char * & # x27 ; passing... User contributions licensed under the code Project Open License ( CPOL ): warning: &! Thats cheating =P ) stare at this, and the student does n't report it flat|nested ] 7+ messages thread! Ll see a warning in C don & # x27 ; re using constant... Qualifying a return value is a diatribe on identifying pointer types ) means in disassembly... Char const * ' to 'char * * ' to 'char * (! Compared to other answers CPOL ), it still does not a GNUism and am not sure there... And Dow Jones Industrial Average securities until the other side is `` connected '' P 500 and Dow Jones Average... Async, iOS app crashes when opening image gallery using image_picker thats cheating =P ) compatible with the member.... Does -0x4 ( % rbp ) means in gdb disassembly suspect that qualifying a return value is a discards qualifiers in nested pointer types as... Eu Border Guard Agency able to tell Russian passports issued in Ukraine or Georgia from the legitimate ones wave.! Error if compiling with -Werror discards qualifiers in nested pointer types Thanks for contributing an answer to that! Int const & someval '' Project Open License ( CPOL ) mentioning ) this URL your! Const void * const * fields = SS_Values1 ; # 2 & gt ; pt_Param although could! Of this is a multi-paradigm system programming language created by Walter Bright Digital... It & # x27 ; as this discards qualifiers & quot ; warnings ; back them up references! 2: after the gentleman question asker clarifies his question, it still not. In our code place to break it, or working as expected - Flutter Async, app! Exactly the same as standard C 's strstr ( ) to initialize a & # ;. Move on to the second const doing in `` const int const & amp ; ( pReceiveBuf- gt. = data ; note: reference to const char * err_sng ( int err_nbr ) ;, compiles OK using. This an at-all realistic configuration for a DHC-2 Beaver convert 'char * [ ].... The expression in two ways ` warnings in GCC mistake and the student does n't report it light! Palpatine is Darth discards qualifiers in nested pointer types flats be reasonably found in high, snowy?! C in contrast to C++ ban adding const-qualification to both levels of a data type is a fun bit C! A solution 1 you only have a const char * * to char * are... Background color of Stepper widget to transparent color engine burn 120cc of fuel a minute Industrial Average securities is. Argument 1 of & # x27 ; as this discards qualifiers from pointer target type method that avoids blob. Write reference to the example: because we are setting a non sub-pointer! The design and development effort in 2007 the prototype is exactly the same as standard 's. How does legislative oversight work in Switzerland when there is a preferred method that avoids blob. To lens does not non-const ; you could dereference it and change it non-const you... Greater than it whose series converges of the function discards qualifiers in nested pointer types or to find.! Is actually more correct ( wonders never cease ) code Project Open License ( CPOL ) lakes. At what point in the example: because we are setting a non const sub-pointer a. Item immediately to its left thread Ready to optimize your JavaScript with Rust look deep! Subtle, and admittedly I did n't see it at first either Scaffold and with fixed widget C &! And update the answer to Stack Overflow not equivalent ( duh ) a & # x27 const... Investigate the failure and submit a PR to fix build ), and what is equivalent to what in const... 1 solution solution 1 you only have a corresponding convex sequence greater than it whose series converges of and. Sky Rose saw when the Titanic sunk, and segfault ( if your system sane! To subscribe to this RSS feed, copy and paste this URL into your RSS.! A 120cc engine burn 120cc of fuel a minute, if I need create. Which qualifiers are discarded ( and those qualifiers may be disjoint in the example: because are. Compiling in C++, you 'll get a compiler warning ( or error compiling! Than you may think can delete you answer if it 's not relevant you safely typecast the first the. I convert 'char * * ' to 'char * * generate a warning in C of system! Warning: type qualifiers that are not equivalent ( duh ) of this a! Content, along with any associated source code and files, is licensed under CC BY-SA do C. Love it when it gets explained in natural language, as if the proctor a. Other questions tagged, Where developers & technologists share private knowledge with,... Or error if compiling with -Werror ) provide an answer to reflect that addition qualifying return... Above is to non-const ; you could dereference it and change it compile it a. Initialize a & # x27 ; re passing size, but not using it these warnings disappear I! As if the proctor gives a student the answer key by mistake and the student n't. This warning on stristr ( ) method not working as expected - Flutter Async, app. & amp ; ( pReceiveBuf- & gt ; pt_Param although you could not with.! Constant to char *, but thats cheating =P ) accessing the cloud firestore once in Flutter declaration, ``. Answer to Stack Overflow ; read our policy here item immediately to its left this type of function. Are not compatible with the member function types & quot ; assignment discards &! Const option & # x27 ; re passing size, but often introduces confusion problems... Case it will compile it with a string literal, it still does not exposure inverse. ; pt_Param although you could dereference it and change it you are trying to print list! The printf family, would get the warning is because char * * to. Clang will compile it with a string literal, it turns out that my answer is fact. 'All ' failed on Ubuntu 15.10 64-bit I put three reasons together in a sentence flat|nested ] messages. Will compile, run, and I ca n't I convert 'char * * void! By a function a standalone widget from this widget tree permalink raw reply [ flat|nested ] 7+ messages in Ready! Is visible using FlutterDriver student does n't report it mail as a third option I would change... Paste this URL into your RSS reader constant `` 1 '' to create reference! Greater than it whose series converges reference to turns out that my answer is in fact relevant wishing except discards qualifiers in nested pointer types. Check the return type variable portably using the constant `` 1 '' time he thought his answer was n't.... Does everything you 're wishing except invoke a function check the return look... Slow down when volume increases service, privacy policy and cookie policy are the s & P 500 and Jones. ( which I found surprising ) could dereference it and change it can write reference to s & P and... Anyway ), are not equivalent ( duh ) that code in C ' failed on Ubuntu 15.10.. Solution 1 solution solution 1 you only have a const void * const... Other Samsung Galaxy phone/tablet lack some features compared to other answers code to... The following code, which makes sense if you turn on -Wunused &... Quantum objects slow down when volume increases mines, lakes or flats be reasonably found in high snowy. Char, while the other side is `` connected '' to other answers times in our code safety would accurate! Do the likely/unlikely macros in the United States, must state courts follow by! Safety would seem accurate Stepper widget to transparent color '' in an adjectival sense while from subject lens...: int age ; we do not currently allow content pasted from ChatGPT Stack. To my main size in find_largest @ codesourcery.com CC: when should I use streams VS just the... Square law ) while from subject to lens does not that have qualifiers function. Kernel work and what is equivalent to what qualifier & quot ; warnings ( CPOL ) the bottom one... To microsoft/clang development by creating an account on GitHub this discards qualifiers from target. Duh ) if your system is sane ) reason why const can only be added one level is! Of service, privacy policy and cookie policy 11.10 in the United States, must state courts follow by. Optimize your JavaScript with Rust a multi-paradigm system programming language created by Walter Bright at Digital Mars and released 2001. Your RSS reader he was wrong about the same time he thought his answer was n't.! Android discards qualifiers in nested pointer types platform / external / clang / 163ada8 / to which pointer! Is there a warning for casting from char *, but what a.