c++

Does acos, atan functions in stl uses lots of cpu cycles

Hi all, I wanted to calculate the angle between two vectors but I have seen these inverse trig operations such as acos and atan uses lots of cpu cycles. Is there a way where I can get this calculation done without using these functions? Also, does these really hit you when you in your optimization? ...

Finding the position of the max element

Is there a standard function that returns the position(not value) of the max element of an array of values? For example: say i have an array like this: sampleArray = [1, 5, 2, 9, 4, 6, 3] I want a function that returns the integer of 3 that tells me that sampleArray[3] is the largest value in the array. ...

unique_ptr boost equivalent?

Is there some equivalent class for C++1x's std::unique_ptr in the boost libraries? The behavior I'm looking for is being able to have an exception-safe factory function, like so... std::unique_ptr<Base> create_base() { return std::unique_ptr<Base>(new Derived); } void some_other_function() { std::unique_ptr<Base> b = create_bas...

In C++, how do I get an int index of an iterator?

I need to cout and return a deque element's index that an iterator is pointing to. How do I get an int out of an iterator? ...

Recycle Freed Objects

suppose I need to allocate and delete object on heap frequently (of arbitrary size), is there any performance benefit if instead of deleting those objects, I will return it back to some "pool" to be reused later? would it give benefit by reduce heap allocation/deallocation?, or it will be slower compared to memory allocator performance,...

Optional structural typing possibilty in C++ or anyother language?

In C++ how to tell compiler that Ogre::Vector3 IS_SAME_AS SomeOtherLIB::Vector3 ? I feel that.. in languages like c++ which are not structural typed but there are cases when it makes sense. Normally as game developer when working with 4+ libraries that provide sort or their own Vector3 implementation. The code is littered with ToOgre, T...

variadic constructors

Are variadic constructors supposed to hide the implicitly generated ones, i.e. the default constructor and the copy constructor? struct Foo { template<typename... Args> Foo(Args&&... x) { std::cout << "inside the variadic constructor\n"; } }; int main() { Foo a; Foo b(a); } Somehow I was expecting this to ...

Why doesn't ADL find function templates?

What part of the C++ specification restricts argument dependent lookup from finding function templates in the set of associated namespaces? In other words, why does the last call in main below fail to compile? namespace ns { struct foo {}; template<int i> void frob(foo const&) {} void non_template(foo const&) {} } int main(...

searching for hidden files using winapi

HI i want to search for a hidden files and directories in a specefic given path but I don't know how to do it for hidden files i do know how to search for normal files and dir i did this code but im stuck can't make it search for only hidden files #include "stdafx.h" #include <windows.h> int _tmain(int argc, _TCHAR* argv[]) { TCHA...

breakpoint inside QComboBox subclass not working

I have subclassed QComboBox to customize it for special needs. The subclass is used to promote QComboBoxes in a ui file from QtDesigner. Everything works except that when I put a break point in a slot, the program does not stop at the breakpoint. I do however know that it is being called from the result it generates. I checked other slot...

the scope of a pointer ???

Ok, so I did find some questions that were almost similar but they actually confused me even more about pointers. http://stackoverflow.com/questions/2715198/c-pointer-objects-vs-non-pointer-objects-closed In the link above, they say that if you declare a pointer it is actually saved on the heap and not on the stack, regardless of wher...

Extract a portion of a Qt .ui file into its own .ui file

We have a designer creating a user interface for an application. The main window has several QStackedWidgets used for in place panel switching. What I'd like to be able to do is extract each individual panel that makes up each page of the QStackedWidget into it its own .ui file. Is there an easy way to accomplish this from within Qt...

Duplicate Symbol Linker Error (C++ help)

Hi. I'm learning some CSP (constraint satisfaction) theory stuff right now, and am using this library to parse XML files. I'm using Xcode as an IDE. My program compiles fine, but when it goes to link the files, I get a duplicate symbol error with the XMLParser_libxml2.hh file. My files are separated as such: A class header file that in...

Convert CString to string (VC6)

I want to convert CString to string. (Yup. I know what am I doing. I know the returned string will be incorrect, if CString value range is outside ANSI, but That's Is OK!) The following code will work under VC2008. std::string Utils::CString2String(const CString& cString) { // Convert a TCHAR string to a LPCSTR CT2CA pszConver...

Need feedback on two member functions of a Table class in C++

int Table::addPlayer(Player const& player, int position) { if (position > 0 || position < 11) { deque<Player>::iterator it = playerList.begin()+position; deque<Player>::iterator itStart = playerList.begin()+postion; while(*it != "(empty seat)") { it++; if (it == playerList.end()) { ...

"variable tracking" is eating my compile time!

I have an auto-generated file which looks something like this... static void do_SomeFunc1(void* parameter) { // Do stuff. } // Continues on for another 4000 functions... void dispatch(int id, void* parameter) { switch(id) { case ::SomeClass1::id: return do_SomeFunc1(parameter); case ::SomeClass2::id: return...

Importing ctype; embedding python in C++ application

I'm trying to embed python within a C++ based programming language (CCL: The compuatational control language, not that any of you have heard of it). Thus, I don't really have a "main" function to make calls from. I have made a test .cc program with a main, and when I compile it and run it, I am able to import my own python modules and s...

how to write a constructor...

is that correct to write a constructor like this? class A { A::A(const A& a) { .... } }; if yes, then is it correct to invoke it like this: A* other; ... A* instance = new A(*(other)); if not, what do you suggest? Thanks ...

Thread Proc for an instancable class?

Basically I have a class and it is instincable (not static). Basically I want the class to be able to generate its own threads and manage its own stuff. I don't want to make a global callback for each instance I make, this doesnt seem clean and proper to me. What is the proper way of doing what I want. If I try to pass the threadproc to ...

how to play rtsp streamming in QT

Hello, I am trying to find a way to play in Qt 4.6 rtsp streaming, that i got from youtube api can it be done somehow? ...