As I understand it, Windows #defines TCHAR as the correct character type for your application based on the build - so it is wchar_t in UNICODE builds and char otherwise. Because of this I wondered if std::basic_string<TCHAR> would be preferable to std::wstring, since the first would theoretically match the character type of the applic...
We had a line of code if( !CreateFile( m_hFile, szFile, GENERIC_READ|GENERIC_WRITE, 0, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL ) ) { DWORD dwErr = GetLastError(); CString czInfo; czInfo.Format ("CMemoryMapFile::OpenAppend SetFilePointer call failed - GetLastError returned %d", dwErr); LOG(czInfo); retu...
In actual C++ standard creating collections satisfying following rules is hard if not impossible: exception safety, cheap internal operations (in actual STL containers: the operations are copies), automatic memory management. To satisfy (1) a collection can't store raw pointers. To satisfy (2) a collection must store raw pointers. To...
Hi all! I work in Linux with c++ (eclipse) and want to use a library. Eclipse shows me an error: undefined reference to 'dlopen' Do you know a solution? Here is my code. #include <stdlib.h> #include <stdio.h> #include <dlfcn.h> int main(int argc, char **argv) { void *handle; double (*desk)(char*); char *error; ha...
Example, I want to specialize a class to have a member variable that is an stl container, say a vector or a list, so I need something like: template <class CollectionType, class ItemType> class Test { public: CollectionType<ItemType> m_collection; }; So I can do: Test t = Test<vector, int>(); t.m_collection<vector<int>> = vector...
Problem In CodeGear C++Builder 2009 we are using the pre-compiled header injection to greatly reduce our compile times. We have the same header file being injected into multiple projects. When compiling some projects, the compiler kicks out the following warning: [BCC32 Warning] Dateutils.hpp(43): W8058 Cannot create pre-compiled head...
Does there exist a collection, that is aware of shared_ptr internals, and avoids regular copying of stored shared_ptr elements in favor of just copying their internal weak pointer? This implicitly means, that no constructor/destructor calls will be done and that there will be no manipulation of shared_ptrs' reference counters. ...
I have the following member data vector<State<T>*> activeChildren; I want to clean-up these pointers in my destructor StateContainer<T>::~StateContainer() { vector<State<T>*>::iterator it = activeChildren.begin(); while(it!=activeChildren.end()) { State<T>* ptr = *it; it = activeChildren.erase(it); delete ...
I've got a minimal app I just created, using VS 2008 SP1 on Vista x64. Its a Console app, created with the wizard, no MFC or anything, I'm building it in 64bit. When I run the debug exe, on my development box, by pressing F5 in Visual Studio 2008, I get this error: TestApp.exe - Unable To Locate Component This application has failed ...
In my epic quest of making C++ do things it shouldn't, I am trying to put together a compile time generated class. Based on a preprocessor definition, such as (rough concept) CLASS_BEGIN(Name) RECORD(xyz) RECORD(abc) RECORD_GROUP(GroupName) RECORD_GROUP_RECORD(foo) RECORD_GROUP_RECORD(bar) END...
I'm working on a program that will parse a PE object for various pieces of information. Reading the specifications though, I cannot find out why the MZ bytes are there, as I cannot find this on the list of machine types that these 2 bytes are supposed to represent. Can anyone clarify? ...
Let's say I have an object Employee_Storage that contains a database connection data member. Should this data member be stored as a pointer or as a reference? If I store it as a reference, I don't have to do any NULL checking. (Just how important is NULL checking anyway?) If I store it as a pointer, it's easier to setup E...
I'd like to work on a 2-3 month long project (full time) that involves coding in C++ and is related to networks (protocol stacks). I was considering writing my own network stack but that doesn't seem as interesting. It would be great to find an idea to implement a tcp/ip-like stack for distributed system/GPUs that is better as far as net...
I have something like this: class Base { public: static int Lolz() { return 0; } }; class Child : public Base { public: int nothing; }; template <typename T> int Produce() { return T::Lolz(); } and Produce<Base>(); Produce<Child>(); both return 0, which is of course correct, but unwanted. Is there anyw...
I often have code based on a specific well defined algorithm. This gets well commented and seems proper. For most data sets, the algorithm works great. But then the edge cases, the special cases, the heuristics get added to solve particular problems with particular sets of data. As number of special cases grow, the comments get more an...
I have three sets of numbers, a measurement (which is in the range 0-1 inclusive) two errors (positive and negative. These numbers should be displayed consistently to the number of significant figures, rounded up, which corresponds to the first non-zero entry in either of the number. This requirement is skipped on the measurement if it...
Hi All, I am implementing a piece of Java software that will hopefully allow for C libraries as plugins. In order to call these future functions I need to somehow create a native function in Java from which I can call the code that doesn't exist yet. The method signature will be static but the method and class names may change. I am ...
Are there any tools for parsing a Visual c++ generated resource script? Is this resource script's format documented any where? I am looking for something in MFC or .net that could parse some data out of the files for reporting. ...
int main() { char *second= new char("hello"); char *first="hi"; char third[]="new"; } I am new to c++ and don't really understand how char works, why the first one give a compiler error, and what are the differences of those 3 way of declaration , the strength and benefits of declaring it in a particular way. Thanks Hmm, a...
Hi I have this code that I found somewhere on stackoverflow that uses libtar and libbz2 to compress a directory: #include <libtar.h> #include <bzlib.h> #include <fcntl.h> #include <string> #include <iostream> using namespace std; int main(int argc, char **argv) { TAR *p_tar; char extract_to[] = "."; char *dst_path = arg...