I am migrating some C++ code from structures to classes. I was using structures mainly for bit-field optimizations which I do not need any more (I am more worried about speed than saving space now). What are the general guidelines for doing this migration? I am still in the planning stage as this is a very big move affecting a major p...
I have a map of objects and I want to update the object mapped to a key, or create a new object and insert into the map. The update is done by a different function that takes a pointer to the object (void update(MyClass *obj)) What is the best way to "insert or update" an element in a map? ...
Hello. I am a beginner, and wrote the following program for fun, to search through a directory and replace every occurrence of one word with another. I call the crt_ls_file() function once, and once only, but gprof tells me it is being called 102 times. I am wondering if anyone knows why this is. I have tried compiling the program will a...
I have a char array which contains null characters at random locations. I tried to create an iStringStream using this array (encodedData_arr) as below, I use this iStringStream to insert binary data(imagedata of Iplimage) to a MySQL database blob field(using MySQL Connector/C++'s setBlob(istream *is) ) it only stores the characters upt...
struct ptr{ int node; ptr *next; ptr(){} ptr(int _node, ptr *_next){ node=_node; next=_next; } }; struct list_t{ ptr *sht; int size; void push(int node){ size++; sht=new ptr(node,sht); } }shthead[100001], comp[200001], tree[200001]; The struct ptr is a smart pointer, be used as a linked l...
hello. Can you tell me how to invoke template constructor explicitly (in initializer list)? for example: struct T { template<class> T(); }; struct U { U() : t<void>() {} //does not work T t; }; thanks ...
I've a C++ program that links at runtime with, lets say, mylib.so. then, the same program uses dlopen()/dlsym() to load a function from myplugin.so, dynamic library that in turn has dependencies to mylib.so. My question is: will the program AND the function in the plugin access the same globals defined in mydlib.so in the same memory ar...
So do I like really need to learn about them ? Isn't there an interesting way to learn about stacks, linked lists, heaps ,etc ? I found it a boring subject. **While posting this question it showed some warning.Am I not allowed to post such a question ? Admins please clarify and I will delete it :/ Warning :: The question you're asking ...
Hi guys! For my small hobby project I need to emit machine code from C++ program in runtime. I have base address 0xDEADBEEF and want to write something like this: Assembler a((void*)0xDEADBEEF); a.Emit() << Push(Reg::Eax) << Push(Reg::Ebx) << Jmp(0xFEFEFEFE); Inline assembler isn't my choice because generated machine code is d...
I'm a little bit scared about something like this: std::map<DWORD, DWORD> tmap; tmap[0]+=1; tmap[0]+=1; tmap[0]+=1; Since DWORD's are not automatically initialized, I'm always afraid of tmap[0] being a random number that is incremented. How does the map know hot to initialize a DWORD if the runtime does not know how to do it? I...
When I set the column text for CListView more than 271 characters, the rest of my buffer is not present. I set it through LV_COLUMN structure. Is this a known issue for MFC 4.21? ...
Hi, I have this destructor that create error at runtime "vector iterator not dereferencable". The gridMatrix is a std::vector<std::vector<std::vector<AtomsCell< Atom<T> * > * > * > * > I added the typename and also the typedef but I still have the error. I will move for this idea of vect of vect* of vect* to use boost::multi_array I ...
I would like to bind the << stream operator: for_each(begin, end, boost::bind(&operator<<, stream, _1)); Unfortunately it does not work: Error 1 error C2780: 'boost::_bi::bind_t<_bi::dm_result<MT::* ,A1>::type,boost::_mfi::dm<M,T>,_bi::list_av_1<A1>::type> boost::bind(M T::* ,A1)' : expects 2 arguments - 3 provided c:\source\repo...
I want to know from where the index of a string and an array starts from. I am getting a lot of confusion while making programs. While calculating string length of a string is the null character also counted? ...
As far as I know, the copy constructor must be of the form T(const T&) or T(T&). What if I wanted to add default arguments to the signature? T(const T&, double f = 1.0); Would that be standards compliant? ...
I have a problem with Visual C++ 2005, where apparently inner classes with the same name but in different outer classes are confused. The problem occurs for two layers, where each layer has a listener interface as an inner class. B is a listener of A, and has its own listener in a third layer above it (not shown). The structure of the ...
I'm developing a Windows Mobile application, and I faced a problem with CCommandBar, which combines toolbar and menubar. Well, I mean the following: m_wndCommandBar.InsertMenuBar(IDR_MAINFRAME); m_wndCommandBar.LoadToolBar(IDR_MAINFRAME); I have only one root menu option in my command bar and some buttons in toolbar. It works perfectl...
class A { public: int i; int j; }; class B : public A { public: int k; }; main() { A *a = new B; } is it possible to access slicing data? ...
i have this code #include <iostream> using namespace std; class Test{ public: int a; Test(int i=0):a(i){} ~Test(){ cout << a << endl; } Test(const Test &){ cout << "copy" << endl; } void operator=(const Test &){ cout << "=" << endl; } Test operator+(Test& p){ Test res(a+p.a); return res; } }; int main (int argc, ch...
Hi guys, Do you know of any C++ libraries can can generate SOAP messages using the WSDL. I am writing a C++ client application and am looking for such a library. I however cannot use gSoap and wsdlpull. SOAP Client library (SQLData Systems) looks like another library which could help me (though I am not too sure) but its results page sh...