I have a class in C++ with the following member: map< someEnum, vector<SomeObject*>* > someMap So I have a map that gives me a vector of objects for each enumeration I have. For the life of me, I cannot understand how C++ is initializing these objects. Does it deep initialize them by default? If not, what do I need to do? I'm getting...
I'm working in C++. I want to write a potentially very long formatted string using sprintf (specifically a secure counted version like _snprintf_s, but the idea is the same). The approximate length is unknown at compile time so I'll have to use some dynamically allocated memory rather than relying on a big static buffer. Is there any ...
It's been a while since I programmed in C++, and after coming from python, I feel soooo in a straight jacket, ok I'm not gonna rant. I have a couple of functions that act as "pipes", accepting a list as input, returning another list as output (based on the input), this is in concept, but in practice, I'm using std::vector to represent...
I have following classes. class A { public: void fun(); } class B: public A { } class C: public A { } A * ptr = new C; Is it ok to do something like below? Will i have some problems if introduce some virtual functions in the baseclass? ((B *)ptr)->fun(); This may look stupid, but i have a function that calls A's function th...
I am learning templates. Which book is worth buying for doing template programming? I already have The C++ Programming Language and Effective C++. ...
I have a Foo object, and a std::list holding instances of it. My problem is that when I add a new instance to the list, it first calls the ctor but then also the dtor. And then the dtor on another instance (according to the this pointer). A single instance is added to the list but since its dtor (along with its parents) is called, the o...
I'm very busy write now debugging some code, so I can't cookup a complete example, but this basically describes my problem class Base{}; class MyX:public Base { ... }; class Derived:Base { ... }; template<class X> class MyClass:Derived { private: MyClass(const MyClass& ) :x() {} public: MyClass(const X& value) :x(...
I have a Linux C++ application and I'd like to test an object pointer for validity before dereferencing it. However try/catch doesn't work for this on Linux because of the segmentation fault. How can this be done? ...
I recently set up, for a learning exercise, an Ubuntu desktop PC with KDE 4.2, installed Eclipse and started to look for information on how to develop for KDE. I know there's KDevelop and will probably have a look at that at some time in the future. Right now, however, I don't have the correct headers and libraries for creating KDE appli...
I have a thread push-backing to STL list and another thread pop-fronting from the list. Do I need to lock the list with mutex in such case? ...
struct TimerEvent { event Event; timeval TimeOut; static void HandleTimer(int Fd, short Event, void *Arg); }; HandleTimer needs to be static since I'm passing it to C library (libevent). I want to inherit from this class. How can this be done? Thanks. ...
C++/CLI helpfully generates the IDisposable scaffolding for you when you implement a destructor on a ref class. Also, if you don't implement a destructor, but your class has a member variable which implements IDisposable, then IDisposable is again automatically implemented on your class. It's pretty helpful and much better than how IDisp...
Do I have to explicitly instantiate a function template's type when it comes to reference type deduction. If that is the case, where is the ambiguity? Let's compare following 2 code snippets: 1st: link for the code template <typename T> void foo(T& var, void(*func)(T&)) // T must be instantiated with int and it does . { ++var; } vo...
std::map<std::string, std::string> myMap; std::map<std::string, std::string>::iterator i = m_myMap.find(some_key_string); if(i == m_imagesMap.end()) return NULL; string *p = &i->first; Is the last line valid? I want to store this pointer p somewhere else, will it be valid for the whole program life? But what will happen if I ad...
There are numerous post over the net that detail how relative paths don't work in Xcode. I do have an Xcode template that I downloaded where the relative paths DO work, however I have not been able to figure out why nor replicate it in other projects. Firstly, I am using C++ in Xcode 3.1. I am not using Objective-C, nor any Cocoa/Carbon...
In my years of C++ (MFC) programming in I never felt the need to use typedef, so I don't really know what is it used for. Where should I use it? Are there any real situations where the use of typedef is preferred? Or is this really more a C-specific keyword? ...
I encountered some code reading typedef enum eEnum { c1, c2 } tagEnum; typedef struct { int i; double d; } tagMyStruct; I heard rumours that these constructs date from C. In C++ you can easily write enum eEnum { c1, c2 }; struct MyStruct { int i; double d; }; Is that true? When do you need the first variant? ...
I need to bind a method into a function-callback, except this snippet is not legal as discussed in demote-boostfunction-to-a-plain-function-pointer. What's the simplest way to get this behavior? struct C { void m(int x) { (void) x; _asm int 3; }}; typedef void (*cb_t)(int); int main() { C c; boost::function<void (int x...
For some reason the integrated debugger is causing an error as soon as I make reference to a third party vendor's dll class. This same code runs when it is built and ran as a release, stand alone. The two properties for debug and release should be the same as I have not really altered them. I added the lib file to the path for both build...
I have a map defined like this std::map<some_key_type, std::string::iterator> mIteratorMap; And a huge string named "mHugeString". Then I walk trough the string collecting iterators like this: std::string::iterator It=mHugeString.begin(); std::string::iterator EndIt=mHugeString.end(); for(;It!=EndIt;++It){ ...defining a key element...