c++

Moving inserted container element if possible

I'm trying to achieve the following optimization in my container library: when inserting an lvalue-referenced element, copy it to internal storage; but when inserting rvalue-referenced element, move it if supported. The optimization is supposed to be useful e.g. if contained element type is something like std::vector, where moving if...

How to change text color on Macintosh? My code uses TESetText and TEUpdate for drawing.

A naive question - i am a novice on mac programming. How to change text color on Macintosh? My code uses TESetText and TEUpdate for drawing. PS - Mac is really really badly documented. ...

Flushing of cout prior to reading input using cin .. why?

Why does cout has to be flushed before cin starts reading? Aren't they of different buffer? I can have reading of input into a buffer while same time putting it on output buffer (before flushing) .. 2 different buffers. I am confused here. ...

I'm a PHP programmer, how easy will it be to "master" c++?

I've been a PHP programmer for 8 or so years, I'm familiar with OOP and try to consider best practices whenever programming. I would like to pick up C++ to possibly enter the 'game development' field, where now I'm doing web dev. I'm not a school person, but was wondering what people think about self-taught math to complement learning ...

ISO C++ forbids declaration of 'QPushButton' with no type in QT Creator

I am running QT Creator on a Linux Ubuntu 9.10 machine. I just got started with QT Creator, and I was going through the tutorials when this error popped up while I was trying to build my project: "ISO C++ forbids declaration of 'QPushButton' with no type". This problem appears in my header file: #ifndef MAINWINDOW_H #define MAINWINDOW_H...

Difference among STLPort and SGI STL

Recently, I was buzzed by the following problem STL std::string class causes crashes and memory corruption on multi-processor machines while using VC6. I plan to use an alternative STL libraries instead of the one provided by VC6. I came across 2 libraries : STLPort and SGI STL I was wondering what is the difference between the 2. Whi...

how to back to the first of text file

i have a txt file which have some lines ...and my code is : string line; ifstream myfile("c:\\main.txt"); bool passport = true; while(passport==true){ int pos1=0; cout<<setw(20)<<"PassPort_Number : "; cin>>add.Id ; if (myfile.is_open()) { while(!myfile.eof()){ getline(myfile,line); ...

Designing a state machine in C++

I have a little problem that involves modeling a state machine. I have managed to do a little bit of knowledge engineering and 'reverse engineer' a set of primitive deterministic rules that determine state as well as state transitions. I would like to know what the best practices are regarding: How to rigorously test my states and st...

Compile/use unrar C++ source for iphone app?

Writing an app that will include the ability to decompress zip and rar files. I think I'm OK on how to handle the .zips but .rars seem a little more trouble. I noticed that rarlabs has source available but it's C++. Is there a way to compile, wrap or otherwise use this code within an iPhone app? Reference: http://www.rarlab.com/rar_add....

struct constructor + function parameter

Hi, I am a C++ beginner. I have the following code, the reult is not what I expect. The question is why, resp. what is wrong. For sure, the most of you see it at the first glance. struct Complex { float imag; float real; Complex( float i, float r) { imag = i; real = r; } Complex( float r) { Co...

Passing a string from C# to cpp with COM

I have a C# COM server which is consumed by a cpp client. One of the C# methods returns a string. In cpp the returned string is represented in Unicode (UTF-16), at least according to the memory view. Is this always the case with COM strings? Is there a way to use UTF-8 instead? I saw some code where strings were passed between cpp an...

Why size_t arguments in template declaration need to be const?

I can have std::bitset< 10 > bitsetA; or const size_t LengthB = 20; std::bitset< LengthB > bitsetB; without any problem. But, if the length is not const size_t LengthC = 30; std::bitset< LengthC > bitsetC; // Line 30, say I face the following compilation error 'LengthC' cannot appear in a constant-expression template arg...

Where does abort() and terminate() "live"?

Regarding the terminate handler, As i understand it, when something bad happens in code, for example when we dont catch an exception, terminate() is called, which in turn calls abort() set_terminate(my_function) allows us to get terminate() to call a user specified function my_terminate. my question is: where do these functions "live...

Debugging MinGW program with gdb on Windows, not terminating at assert failure

How do I set up gdb on window so that it does not allow a program with assertion failure to terminate? I intend to check the stack trace and variables in the program. For example, running this test.cpp program compiled with MinGW 'g++ -g test.cpp -o test' in gdb: #include <cassert> int main(int argc, char ** argv) { assert(1==2); retu...

1>Project : error PRJ0003 : Error spawning 'rc.exe'.

1>Project : error PRJ0003 : Error spawning 'rc.exe'.. this is the error i get when i try to run this small practice program of reading and writing files which i cant do because of the reason of me not being able to get the files to open correctly. i use microsoft visual c++ 2008 and i have used the file path to try to open the file as w...

runtime library and global namespace

Does the runtime library pollute the global namespace? ...

using string to read file - Xcode

The following does not work and gives me a SIGABRT when I run in the debugger: std::ifstream inFile; inFile.open("/Users/fernandonewyork/inputText.txt"); cout << inFile << endl; vector<string> inText; if (inFile) { string s4; while (inFile>>s4) { inText.push_back(s4); } } inFile.close(); The following...

ID generator with local static variable - thread-safe?

Will the following piece of code work as expected in a multi-threaded scenario? int getUniqueID() { static int ID=0; return ++ID; } It's not necessary that the IDs to be contiguous - even if it skips a value, it's fine. Can it be said that when this function returns, the value returned will be unique across all threa...

[C++] My First Go With Function Templates

Thought it was pretty straight forward. But I get a "iterator not dereferencable" errro when running the below code. What's wrong? template<typename T> struct SumsTo : public std::binary_function<T, T, bool> { int myInt; SumsTo(int a) { myInt = a; } bool operator()(const T& l, const T& r) { c...

"error: Expected a type, got 'classname'" in C++

Using the following code: template <typename T> class node { [. . .] }; class b_graph { friend istream& operator>> (istream& in, b_graph& ingraph); friend ostream& operator<< (ostream& out, b_graph& outgraph); public: [...] private: vector<node> vertices; //This line I'm getting: error: type/value mismatch at argument ...