Is there a method to automatically find the best compiler options (on a given machine), which result in the fastest possible executable? Naturally, I use g++ -O3, but there are additional flags that may make the code run faster, e.g. -ffast-math and others, some of which are hardware-dependent. Does anyone know some code I can put in...
A company I am working for, has some c binaries build with ant using cpptask. They use ivy to retrieve shared c libraries every time we start a build which wastes a significant amount of time comparing the revisions and downloading, when then only need to be download if the header files have changed. I have added a target which sets a va...
I want to print two strings (say "ABC" and "DEF") with 5 space characters before "ABC" and that the second string will start 7 characters after the beginning of the first string. ...
I've noticed that a lot of Objective-C examples will forward declare classes with @class, then actually import the class in the .m file with an import. I understand that this is considered a best practice, as explained in answers to question: http://stackoverflow.com/questions/322597/objective-c-class-vs-import Coming from C++ this fee...
Is it possible to print a random number in C++ from a set of numbers with ONE SINGLE statement? let's say the set is 2, 5, 22, 55, 332 i looked up rand, but I double it's possible to do in a single statement ...
Hi, guys I know this question is very basic but I've met in few publications (websites, books) different style of override virtual function. What I mean is: if I have base class: class Base { public: virtual void f() = 0; }; in some publications I saw that to override this some authors would just say: void f(); and some would ...
i am writing a visual basic ide , and i need to add lines numbers to QTextEdit and highlight current line . i have found this tutorial but it is written in java and i write my project in c++ so where to find tutorial like that in c++ , or if there is a ready to use component ? thanks . ...
When should I inline a member function and when should I use member initializers? My code is below.. I would like to modify it so I could make use some inline when appropriate and member initializers: #include "Books.h" Book::Book(){ nm = (char*)""; thck = 0; wght = 0; } Book::Book(const char *name, int thickness, int weight){ ...
MSDN documentation seems silent on whether RegCreateKeyEx ever updates the value of the handle referred to by its second-last parameter when it fails. My tests have only shown it not to update this - i.e., I set h = 0 before the call, pass &h to a call to RegCreateKeyEx to open a non-existent key, and see h = 0 after the call. Does anyon...
Hi there. I'm setting up a VC++ project in MS Visual Studio 2008 that'll be used by several people. I wanted to keep things as simple as possible so I've set up Additional Include Directories via the Project properties. I've also set up additional library files via Tools -> Options -> Projects and Solutions -> VC++ Directories. However...
How does C++ determine implicit conversion/construction of objects few levels deep? for example: struct A {}; struct B: A {}; struct C { operator B() { return B(); } }; void f(A a) {} int main(void) { f(C()); } Does it create tree of all possible conversions and chooses appropriate terminal? Something else? Thanks ...
I got some problems with EOF and stdio in a communication pipeline between a python process and a C++ program. I have no idea what I am doing wrong. When I see an EOF in my program I clear the stdin and next round I try to read in a new line. The problem is: for some reason the getline function immediatly (from the second run always, the...
I've been searching examples for the Win32 API C++ function TerminateProcess() but couldn't find any. I'm not that familiar with the Win32 API in general and so I wanted to ask if someone here who is better in it than me could show me an example for, Retrieving a process handle by its PID required to terminate it and then call Termina...
class Node{ private: string name; Node** adjacent; int adjNum; public: Node(); Node(string, int adj_num); Node(const Node &); bool addAdjacent(const Node &); Node** getAdjacents(); string getName(); ...
What is exactly the difference between the "old" Managed C++ and the "new" C++/CLI? ...
I'm creating a 2D game and want to test for collision between an OBB (Oriented Bounding Box) and a Circle. I'm unsure of the maths and code to do this. I'm creating the game in c++ and opengl. ...
I have an Entity class, which contains 3 pointers: m_rigidBody, m_entity, and m_parent. Somewhere in Entity::setModel(std::string model), it's crashing. Apparently, this is caused by bad data in m_entity. The weird thing is that I nulled it in the constructor and haven't touched it since then. I debugged it and put a watchpoint on it, an...
Hi, I want to create a unique hash (16 chars long) of an arbitrary length String. Is there a good library that implements MD5 or SHA-1 for C++ with which I can achieve this? (and possibly an example of how to use it) ...
I am using strdup here to copy the value of the parameter name into nm in the constructor... is there an alternative of achieving the same result without using strdup and without using the C++ STL library and using the keyword new instead? Book::Book(const char *name, int thickness, int weight):nm(NULL), thck(thickness), wght(weight){ ...
Problem Hello all! I have this code which takes my jpg image loops through altering pixels and finally saving it as a png type. The problem is that the resulting image has a bit depth of 32 bits. I need it to be 24 bit, can any one shiny some light on the correct method of setting it? Am I along the right tracks looking at setting the ...