typedef struct temp { int a,b; char *c; temp(){ c = (char*)malloc(10);}; ~temp(){free(c);}; }temp; int main() { temp a; list<temp> l1; l1.push_back(a); l1.clear(); return 0; } giving segmentation fault. ...
How does one differentiate between pointers and references at runtime? For example, if I wanted to free a pointer of a data type without knowing whether it were a pointer or not how would I do so? Is there any method to tell if a variable has been allocated on the stack or through malloc()? void destInt(int* var) { free(var); } int...
Hello, Awhile ago I asked you another question(Click here to view the question). This is my problem when using that source file you gave me: public unsafe struct tPacket_5000_E { public Int16 size; public Int16 opcode; public byte securityCount; public byte securityCRC; public byte flag; fixed byte blowfish[8];...
C++ code: struct tPacket { WORD word1; WORD word2; BYTE byte1; BYTE byte2; BYTE array123[8]; } static char data[8192] = {0}; ... some code to fill up the array ... tPacket * packet = (tPacket *)data; We can't do that as easy in C#. Please note there is an array in the C++ structure. Alternatively, using this sou...
Hi, I am having quite a bit of trouble with trying to push_back an object of my custom class to a vector of pointers with my custom class as the type. Please see the code below along with the error received. I am using Eclipse with the CDT plugin and OpenCV on windows xp. I have spent so much time trying to find an answer but to no ava...
Hello, I have a function that generates a CRC check byte based on the content of any packet.The problem is in translating the function from C++ to C# C++ code: unsigned char GenerateCheckByte( char* packet, int length, unsigned long seed ) { if( !packet ) return 0; unsigned long checksum = 0xFFFFFFFF; length &= 0x7FFF; char* ptr = pac...
Duplicate Do you use NULL or 0 for pointers in C++? When dealing with NULL pointers one can do this if(ptr != NULL){ ... } or this if(ptr != 0){ ... } Are there reasons to prefer one over the other in C++? ...
I'm having a problem saving a vary large database type in Delphi. It contains an array[1..3500] of TItem, which in turn has two arrays[1..50] and [1..20]. I get a stack overflow unless I set the variable as a Pointer and use the GetMem, FreeMem commands below, but then I can't save it. Code is below. procedure TDatabase.SaveDB; var ...
Use case: class B { int b; public: int getB() { return b; } }; class A { B *b; public: int getB() { if (b ) { //How can I avoid the null check for b here return b->getB(); } } } ...
What are some ways you can shoot yourself in the foot when using boost::shared_ptr? In other words, what pitfalls do I have to avoid when I use boost::shared_ptr? ...
Alright, I think we all agree that what happens with the following code is undefined, depending on what is passed void deleteForMe(int* pointer) { delete[] pointer; } The pointer could be all sorts of different things, and so performing an unconditional delete[] on it is undefined. However, let's assume that we are indeed passing...
I'm working on a small little thing here for school. After hours of researching, and a ton of errors and logic reworking I've almost completed my little program here. I'm trying to take user input, store it into the string, get a character array from the string ( dont ask why, I just have to put this into a character array ), then get t...
I'm trying to use python ctypes to use these two C functions from a shared library: bool decompress_rgb(unsigned char *data, long dataLen, int scale) float* getRgbBuffer() The first function is working fine. I can tell by putting some debug code in the shared library and checking the input. The problem is getting the data out. The RG...
EDIT: ah, there it is! Problem solved, thank you! (Bug was elsewhere, not in the copy function.) I'm working with a program that uses two-dimensional arrays of Strings (probably not that smart to begin with, but eh), and I'd like to write a function that takes one of these arrays (let's say array1), makes an independent copy, and retur...
I have a dictionary that goes like this: typedef struct dictNode { int key; char *value; struct dictNode *next; } Dict; And a get() function that goes like this: char *get(const Dict *dict, int key) { if(!dict) return NULL; Dict *currPtr = dict; while(currPtr) { if(currPtr->key == key) { return cu...
I have a small gif that I can use as a mouse pointer with a browser by doing something like: .myclass { cursor: url("mycursor.gif"); } This works OK except that the hotspot is in the wrong place. Anyone know of any OSX Leopard software I can use to set the hotspot? I might be able to do it with Rezilla but I don't know ...
In ANSI C, offsetof is defined as below. #define offsetof(st, m) \ ((size_t) ( (char *)&((st *)(0))->m - (char *)0 )) Why won't this throw a segmentation fault since we are dereferencing a NULL pointer? Or is this some sort of compiler hack where it sees that only address of the offset is taken out, so it statically calculates the...
I would like to dynamically control code execution using a pointer, basically a function pointer without the stack frame. Execution does not return to the calling location, but to a single point. TopOfLoop: ... Jump(x) x1: ... continue x2: ... continue etc. Is this possible in c#? Thanks. ...
Hey all. I'm working on a project for school where I need to pass a few parameters by reference through multiple functions. I understand how I can pass by reference from where the variables are declared to another function, like this: main() { int x = 0; int y = 0; int z = 0; foo_function(&x, &y, &z); } int foo_function(int* x, int* ...
Hi, Can I expect that any "data" pointer in user space programs lies in a safe distance from the addresses 0 and 0xffffffff..., so that I can safely add a small offset to the pointer without checking for an overflow? What is the largest positive n for which I can safely assume that p + n doesn't overflow when p is a char pointer into a ...