Search Results

Search found 10366 results on 415 pages for 'const char pointer'.

Page 236/415 | < Previous Page | 232 233 234 235 236 237 238 239 240 241 242 243  | Next Page >

  • Implementing default constructors

    - by James
    Implement the default constructor, the constructors with one and two int parameters. The one-parameter constructor should initialize the first member of the pair, the second member of the pair is to be 0. Overload binary operator + to add the pairs as follows: (a, b) + (c, d) = (a + c, b + d); Overload the - analogously. Overload the * on pairs ant int as follows: (a, b) * c = (a * c, b * c). Write a program to test all the member functions and overloaded operators in your class definition. You will also need to write accessor (get) functions for each member. The definition of the class Pairs: class Pairs { public: Pairs(); Pairs(int first, int second); Pairs(int first); // other members and friends friend istream& operator>> (istream&, Pair&); friend ostream& operator<< (ostream&, const Pair&); private: int f; int s; }; Self-Test Exercise #17: istream& operator (istream& ins, Pair& second) { char ch; ins ch; // discard init '(' ins second.f; ins ch; // discard comma ',' ins second.s; ins ch; // discard final '(' return ins; } ostream& operator<< (ostream& outs, const Pair& second) { outs << '('; outs << second.f; outs << ", " ;// I followed the Author's suggestion here. outs << second.s; outs << ")"; return outs; }

    Read the article

  • Fundamental types

    - by smerlin
    I always thought the following types are "fundamental types", so i thought my anwser to this question would be correct, but surprisingly it got downvoted... Searching the web, i found this. So, IBM says aswell those types are fundamental types.. Well how do you interpret the Standard, are following types (and similar types), "fundamental types" according to the c++ standard ? unsigned int signed char long double long long long long int unsigned long long int

    Read the article

  • Implications of trying to double free memory space in C

    - by SidNoob
    Here' my piece of code: #include <stdio.h> #include<stdlib.h> struct student{ char *name; }; int main() { struct student s; s.name = malloc(sizeof(char *)); // I hope this is the right way... printf("Name: "); scanf("%[^\n]", s.name); printf("You Entered: \n\n"); printf("%s\n", s.name); free(s.name); // This will cause my code to break } All I know is that dynamic allocation on the 'heap' needs to be freed. My question is, when I run the program, sometimes the code runs successfully. i.e. ./struct Name: Thisis Myname You Entered: Thisis Myname I tried reading this I've concluded that I'm trying to double-free a piece of memory i.e. I'm trying to free a piece of memory that is already free? (hope I'm correct here. If Yes, what could be the Security Implications of a double-free?) While it fails sometimes as its supposed to: ./struct Name: CrazyFishMotorhead Rider You Entered: CrazyFishMotorhead Rider *** glibc detected *** ./struct: free(): invalid next size (fast): 0x08adb008 *** ======= Backtrace: ========= /lib/tls/i686/cmov/libc.so.6(+0x6b161)[0xb7612161] /lib/tls/i686/cmov/libc.so.6(+0x6c9b8)[0xb76139b8] /lib/tls/i686/cmov/libc.so.6(cfree+0x6d)[0xb7616a9d] ./struct[0x8048533] /lib/tls/i686/cmov/libc.so.6(__libc_start_main+0xe6)[0xb75bdbd6] ./struct[0x8048441] ======= Memory map: ======== 08048000-08049000 r-xp 00000000 08:01 288098 /root/struct 08049000-0804a000 r--p 00000000 08:01 288098 /root/struct 0804a000-0804b000 rw-p 00001000 08:01 288098 /root/struct 08adb000-08afc000 rw-p 00000000 00:00 0 [heap] b7400000-b7421000 rw-p 00000000 00:00 0 b7421000-b7500000 ---p 00000000 00:00 0 b7575000-b7592000 r-xp 00000000 08:01 788956 /lib/libgcc_s.so.1 b7592000-b7593000 r--p 0001c000 08:01 788956 /lib/libgcc_s.so.1 b7593000-b7594000 rw-p 0001d000 08:01 788956 /lib/libgcc_s.so.1 b75a6000-b75a7000 rw-p 00000000 00:00 0 b75a7000-b76fa000 r-xp 00000000 08:01 920678 /lib/tls/i686/cmov/libc-2.11.1.so b76fa000-b76fc000 r--p 00153000 08:01 920678 /lib/tls/i686/cmov/libc-2.11.1.so b76fc000-b76fd000 rw-p 00155000 08:01 920678 /lib/tls/i686/cmov/libc-2.11.1.so b76fd000-b7700000 rw-p 00000000 00:00 0 b7710000-b7714000 rw-p 00000000 00:00 0 b7714000-b7715000 r-xp 00000000 00:00 0 [vdso] b7715000-b7730000 r-xp 00000000 08:01 788898 /lib/ld-2.11.1.so b7730000-b7731000 r--p 0001a000 08:01 788898 /lib/ld-2.11.1.so b7731000-b7732000 rw-p 0001b000 08:01 788898 /lib/ld-2.11.1.so bffd5000-bfff6000 rw-p 00000000 00:00 0 [stack] Aborted So why is it that my code does work sometimes? i.e. the compiler is not able to detect at times that I'm trying to free an already freed memory. Has it got to do something with my stack/heap size?

    Read the article

  • What are function pointers good for ?

    - by gramm
    Hi, I have trouble seing the utility of the function pointers. I guess it may be useful in some case (it exists, after all), but I can't think of a case where it's better or unavoidable to use a function pointer. Could you give some example of good use of function pointers (in C or C++)? Many thanks :)

    Read the article

  • Cocoa : How do I catch drag operations initiated from an IKBrowserView?

    - by bucketmouse
    So I've got an IKBrowserView all wired up and happily dragging my custom datatype (provided lazily via PasteboardItem) from one window to another, but now I'm interested in detecting when the user drops some data onto the trashcan. Cocoa's documentation says to check the return type of the drag operation itself, but how exactly do I do this with an IKBrowserView? Once I call imageBrowser:writeItemsAtIndexes:toPasteboard: I don't seem to get any notifications other than the request for the pasteboard contents, which doesn't provide a pointer to the drag operation that invoked it.

    Read the article

  • Parsing numbers at PreviewTextInput

    - by Nitin Chaudhari
    I have a WPF application in which I have a hook at PreviewTextInput, through that I get the currently entered character and I have the string already entered. Given this I need to write the following function : bool ShouldAccept(char newChar,string existingText) existingText can be comma seperated valid numbers(including exponential) and it should just return false when invalid characters are pressed. My code(if else based) currently has a lot of flaws, I wanted to know if there is any smart way to do it.

    Read the article

  • C# hash password create salt question

    - by 5YrsLaterDBA
    If I create salt by using something like this: public class User { private const int Hash_Salt_Length = 8; private byte[] saltBytes = new byte[Hash_Salt_Length]; public User() { RNGCryptoServiceProvider rng = new RNGCryptoServiceProvider(); rng.GetNonZeroBytes(saltBytes); } .... } The saltBytes bytes array will be different for each session (restart the application). How can I check password to allow user login our application?

    Read the article

  • Is there a way to prevent a string of letters with no spaces from overflowing out of its correspondi

    - by Scarface
    The question is pretty straight forward, I have tried using a span with rules set to clear:both; and display:block;, at the bottom of each list entry where the text is being inserted in with no luck. I am not really sure what to do on this. I don't expect to many entries with long consecutive letter strings but for example if someone does lolololololol or ahaahahahhhhhhhhhhhhaaaaaaaa for like 100 letters, it will overflow. If anyone can give me a pointer I would really appreciate it.

    Read the article

  • wireless profile saving problem please help me out

    - by Jayjitraj
    DATA_BLOB in; DATA_BLOB out; BYTE pin=(BYTE)"FIPL2"; DWORD din=strlen((char*)pin)+1; in.pbData = pin; in.cbData = din; if(CryptProtectData(&in,L"what is it",NULL,NULL,NULL,0,&out)) { BYTE *b=out.pbData; Now I want to convert it into hexadecimal to save as my wifi password so what should i do }

    Read the article

  • Jumping into argv?

    - by jth
    Hi, I`am experimenting with shellcode and stumbled upon the nop-slide technique. I wrote a little tool that takes buffer-size as a parameter and constructs a buffer like this: [ NOP | SC | RET ], with NOP taking half of the buffer, followed by the shellcode and the rest filled with the (guessed) return address. Its very similar to the tool aleph1 described in his famous paper. My vulnerable test-app is the same as in his paper: int main(int argc, char **argv) { char little_array[512]; if(argc>1) strcpy(little_array,argv[1]); return 0; } I tested it and well, it works: jth@insecure:~/no_nx_no_aslr$ ./victim $(./exploit 604 0) $ exit But honestly, I have no idea why. Okay, the saved eip was overwritten as intended, but instead of jumping somewhere into the buffer, it jumped into argv, I think. gdb showed up the following addresses before strcpy() was called: (gdb) i f Stack level 0, frame at 0xbffff1f0: eip = 0x80483ed in main (victim.c:7); saved eip 0x154b56 source language c. Arglist at 0xbffff1e8, args: argc=2, argv=0xbffff294 Locals at 0xbffff1e8, Previous frame's sp is 0xbffff1f0 Saved registers: ebp at 0xbffff1e8, eip at 0xbffff1ec Address of little_array: (gdb) print &little_array[0] $1 = 0xbfffefe8 "\020" After strcpy(): (gdb) i f Stack level 0, frame at 0xbffff1f0: eip = 0x804840d in main (victim.c:10); saved eip 0xbffff458 source language c. Arglist at 0xbffff1e8, args: argc=-1073744808, argv=0xbffff458 Locals at 0xbffff1e8, Previous frame's sp is 0xbffff1f0 Saved registers: ebp at 0xbffff1e8, eip at 0xbffff1ec So, what happened here? I used a 604 byte buffer to overflow little_array, so he certainly overwrote saved ebp, saved eip and argc and also argv with the guessed address 0xbffff458. Then, after returning, EIP pointed at 0xbffff458. But little_buffer resides at 0xbfffefe8, that`s a difference of 1136 byte, so he certainly isn't executing little_array. I followed execution with the stepi command and well, at 0xbffff458 and onwards, he executes NOPs and reaches the shellcode. I'am not quite sure why this is happening. First of all, am I correct that he executes my shellcode in argv, not little_array? And where does the loader(?) place argv onto the stack? I thought it follows immediately after argc, but between argc and 0xbffff458, there is a gap of 620 bytes. How is it possible that he successfully "lands" in the NOP-Pad at Address 0xbffff458, which is way above the saved eip at 0xbffff1ec? Can someone clarify this? I have actually no idea why this is working. My test-machine is an Ubuntu 9.10 32-Bit Machine without ASLR. victim has an executable stack, set with execstack -s. Thanks in advance.

    Read the article

  • gcc optimization? bug? and its practial implication to project

    - by kumar_m_kiran
    Hi All, My questions are divided into three parts Question 1 Consider the below code, #include <iostream> using namespace std; int main( int argc, char *argv[]) { const int v = 50; int i = 0X7FFFFFFF; cout<<(i + v)<<endl; if ( i + v < i ) { cout<<"Number is negative"<<endl; } else { cout<<"Number is positive"<<endl; } return 0; } No specific compiler optimisation options are used or the O's flag is used. It is basic compilation command g++ -o test main.cpp is used to form the executable. The seemingly very simple code, has odd behaviour in SUSE 64 bit OS, gcc version 4.1.2. The expected output is "Number is negative", instead only in SUSE 64 bit OS, the output would be "Number is positive". After some amount of analysis and doing a 'disass' of the code, I find that the compiler optimises in the below format - Since i is same on both sides of comparison, it cannot be changed in the same expression, remove 'i' from the equation. Now, the comparison leads to if ( v < 0 ), where v is a constant positive, So during compilation itself, the else part cout function address is added to the register. No cmp/jmp instructions can be found. I see that the behaviour is only in gcc 4.1.2 SUSE 10. When tried in AIX 5.1/5.3 and HP IA64, the result is as expected. Is the above optimisation valid? Or, is using the overflow mechanism for int not a valid use case? Question 2 Now when I change the conditional statement from if (i + v < i) to if ( (i + v) < i ) even then, the behaviour is same, this atleast I would personally disagree, since additional braces are provided, I expect the compiler to create a temporary built-in type variable and them compare, thus nullify the optimisation. Question 3 Suppose I have a huge code base, an I migrate my compiler version, such bug/optimisation can cause havoc in my system behaviour. Ofcourse from business perspective, it is very ineffective to test all lines of code again just because of compiler upgradation. I think for all practical purpose, these kinds of error are very difficult to catch (during upgradation) and invariably will be leaked to production site. Can anyone suggest any possible way to ensure to ensure that these kind of bug/optimization does not have any impact on my existing system/code base? PS : When the const for v is removed from the code, then optimization is not done by the compiler. I believe, it is perfectly fine to use overflow mechanism to find if the variable is from MAX - 50 value (in my case).

    Read the article

  • I want to trace logs using a Macro multi parameter always null. problem c++ windows

    - by sxingfeng
    I am using the following way to cout a function's time: #define TIME_COST(message, ...)\ char szMessageBuffer[2048] = {0};\ va_list ArgList;\ va_start(ArgList, message);\ vsprintf_s(szMessageBuffer, 2048, message, ArgList);\ va_end(ArgList); \ string strMessage(szMessageBuffer);\ CQLogTimer t(strMessage); // CQLogTimer is a self destructor,which will cout life time of its own and print szMessageBuffer. However when I use the macro this : void fun { TIME_COST("hello->%s", filePath); XXXXXX } The message generated always is hello-(null) Can Any one help? Many thanks!

    Read the article

  • How can I hash a string to an int using c++?

    - by zebraman
    I have to write my own hash function. If I wanted to just make the simple hash function that maps each letter in the string to a numerical value (i.e. a=1, b=2, c=3, ...), is there a way I can perform this hash on a string without having to first convert it to a c-string to look at each individual char? Is there a more efficient way of hashing strings?

    Read the article

  • MySQL doesn't use index in join query

    - by Kocsonya Laci
    I have two tables: comments(id(primary key), author, ip(index)) and visitors(id(primary key), date_time, ip(index)) I want to join them like that: SELECT visitors.date_time FROM comments LEFT JOIN visitors ON ( comments.ip = visitors.ip ) WHERE comments.author = 'author' LIMIT 10 It works, but very slow.. In EXPLAIN it shows that it doesn't use the index on the visitors table: id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE comments ref author author 78 const 9660 Using where 1 SIMPLE visitors ALL NULL NULL NULL NULL 8033 Any ideas? Thanks!

    Read the article

  • Function overloading

    - by makcoozi
    I found this code , and i m not sure that whether overloading should happen or not. void print( int (*arr)[6], int size ); void print( int (*arr)[5], int size ); what happens if I pass pointer to an array of 4 elements , to it should come... any thread will be helpful.

    Read the article

  • OpenCL books/tutorials?

    - by StfnoPad
    Is there any openCL books out there? or in the pipeline? Any online openCL tutorial? I already looked at the usual pages like khronos/nvidia dev/opengl.org/ati dev/siggraph slides. Any other help or pointer is welcome :-D Thanks!

    Read the article

  • Error while conversion of string to datetime

    - by aswathi
    The conversion of a char data type to a DateTime data type resulted in an out-of-range DateTime value. The statement has been terminated. Please give me most possible answers ALTER PROCEDURE [dbo].[attendance_updatebyemployee_id] @Employee_id int, @AtDate datetime, @FNLogged bit, @ANLogged bit, @LogTime varchar(10), @LogOuttime varchar(10) AS BEGIN SET NOCOUNT ON; update Mst_Attendance set FNLogged=@FNLogged, ANLogged=@ANLogged,LogTime=@LogTime,LogOuttime=@LogOuttime where EmployeeId=@Employee_id and Atdate= @AtDate END

    Read the article

  • Syntax explanation

    - by Knowing me knowing you
    In code: struct tagPaint { }Paint,//<<<--------------what's this (Paint)? *pPaint;//<<<-------------and this(*pPaint)? I mean do I declare variable with name Paint of type tagPaint and pointer called pPaint to tagPaint? Thanks.

    Read the article

  • decltype, result_of, or typeof?

    - by Neil G
    I have: class A { public: B toCPD() const; And: template<typename T> class Ev { public: typedef result_of(T::toCPD()) D; After instantiating Ev<A>, the compiler says: meta.h:12: error: 'T::toCPD' is not a type neither decltype nor typeof work either.

    Read the article

  • Error:A generic error occurred in GDI+

    - by sanfra1983
    Hi, I created a web project on the server, and when I upload an image shows me the error Error: A generic error occurred in GDI +. I have read many links on the net that talk about this issue, and although I made the changes, nothing went wrong. I was thinking if the case is not an issue of permissions to folders. In fact I have two folders one inside the other. This is the code to resize the image: public Bitmaps ResizeImage (Stream stream, int? width, int? height) ( System.Drawing.Bitmap bmpOut = null; const int defaultWidth = 800; const int defaultHeight = 600; int width = lnWidth == null? defaultWidth: (int) width; int height = lnHeight == null? defaultHeight: (int) height; try ( LoBMP bitmap = new Bitmap (stream); ImageFormat loFormat = loBMP.RawFormat; decimal lnRatio; lnNewWidth int = 0; lnNewHeight int = 0; if (loBMP.Width <& & lnWidth loBMP.Height <lnHeight) ( loBMP return; ) if (loBMP.Width> loBMP.Height) ( lnRatio = (decimal) lnWidth / loBMP.Width; lnNewWidth = lnWidth; decimal = lnTemp loBMP.Height lnRatio *; lnNewHeight = (int) lnTemp; ) else ( lnRatio = (decimal) lnHeight / loBMP.Height; lnNewHeight = lnHeight; decimal = lnTemp loBMP.Width lnRatio *; lnNewWidth = (int) lnTemp; ) bmpOut = new Bitmap (lnNewWidth, lnNewHeight); Graphics g = Graphics.FromImage (bmpOut); g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic; g.FillRectangle (Brushes.White, 0, 0, lnNewWidth, lnNewHeight); g.DrawImage (loBMP, 0, 0, lnNewWidth, lnNewHeight); loBMP.Dispose (); ) catch ( return null; ) bmpOut return; ) and this is the code that I insert in the codebehind: string filepath = AppDomain.CurrentDomain.BaseDirectory + img_veterinario / "; string = filepathM AppDomain.CurrentDomain.BaseDirectory + img_veterinario / img_veterinarioM; Reseize Reseize R = new (); Bitmap = photosFileOriginal r.ResizeImage (fucasiclinici.PostedFile.InputStream, 400, 400); Bitmap = photosFileMiniatura r.ResizeImage (fucasiclinici.PostedFile.InputStream, 72, 72); String filename = Path.GetFileName (fucasiclinici.PostedFile.FileName); photosFileOriginal.Save (Path.Combine (filepath, filename)); photosFileMiniatura.Save (Path.Combine (filepathM, filename)); Can you help me? Thanks

    Read the article

  • functional, bind1st and mem_fun

    - by Neil G
    Why won't this compile? #include <functional> #include <boost/function.hpp> class A { A() { typedef boost::function<void ()> FunctionCall; FunctionCall f = std::bind1st(std::mem_fun(&A::process), this); } void process() {} }; Errors: In file included from /opt/local/include/gcc44/c++/bits/stl_function.h:712, from /opt/local/include/gcc44/c++/functional:50, from a.cc:1: /opt/local/include/gcc44/c++/backward/binders.h: In instantiation of 'std::binder1st<std::mem_fun_t<void, A> >': a.cc:7: instantiated from here /opt/local/include/gcc44/c++/backward/binders.h:100: error: no type named 'second_argument_type' in 'class std::mem_fun_t<void, A>' /opt/local/include/gcc44/c++/backward/binders.h:103: error: no type named 'first_argument_type' in 'class std::mem_fun_t<void, A>' /opt/local/include/gcc44/c++/backward/binders.h:106: error: no type named 'first_argument_type' in 'class std::mem_fun_t<void, A>' /opt/local/include/gcc44/c++/backward/binders.h:111: error: no type named 'second_argument_type' in 'class std::mem_fun_t<void, A>' /opt/local/include/gcc44/c++/backward/binders.h:117: error: no type named 'second_argument_type' in 'class std::mem_fun_t<void, A>' /opt/local/include/gcc44/c++/backward/binders.h: In function 'std::binder1st<_Operation> std::bind1st(const _Operation&, const _Tp&) [with _Operation = std::mem_fun_t<void, A>, _Tp = A*]': a.cc:7: instantiated from here /opt/local/include/gcc44/c++/backward/binders.h:126: error: no type named 'first_argument_type' in 'class std::mem_fun_t<void, A>' In file included from /opt/local/include/boost/function/detail/maybe_include.hpp:13, from /opt/local/include/boost/function/detail/function_iterate.hpp:14, from /opt/local/include/boost/preprocessor/iteration/detail/iter/forward1.hpp:47, from /opt/local/include/boost/function.hpp:64, from a.cc:2: /opt/local/include/boost/function/function_template.hpp: In static member function 'static void boost::detail::function::void_function_obj_invoker0<FunctionObj, R>::invoke(boost::detail::function::function_buffer&) [with FunctionObj = std::binder1st<std::mem_fun_t<void, A> >, R = void]': /opt/local/include/boost/function/function_template.hpp:913: instantiated from 'void boost::function0<R>::assign_to(Functor) [with Functor = std::binder1st<std::mem_fun_t<void, A> >, R = void]' /opt/local/include/boost/function/function_template.hpp:722: instantiated from 'boost::function0<R>::function0(Functor, typename boost::enable_if_c<boost::type_traits::ice_not::value, int>::type) [with Functor = std::binder1st<std::mem_fun_t<void, A> >, R = void]' /opt/local/include/boost/function/function_template.hpp:1064: instantiated from 'boost::function<R()>::function(Functor, typename boost::enable_if_c<boost::type_traits::ice_not::value, int>::type) [with Functor = std::binder1st<std::mem_fun_t<void, A> >, R = void]' a.cc:7: instantiated from here /opt/local/include/boost/function/function_template.hpp:153: error: no match for call to '(std::binder1st<std::mem_fun_t<void, A> >) ()'

    Read the article

< Previous Page | 232 233 234 235 236 237 238 239 240 241 242 243  | Next Page >