c++

how to print std::map value in gdb

Hi all I have a std::map< std::string, std::string> cont; I want to see cont[ "some_key" ] in gdb. When I'm trying p cont[ "some_ket" ] I'm getting this message: One of the arguments you tried to pass to operator[] could not be converted to what the function wants. I'm using GNU gdb Red Hat Linux (6.3.0.0-1.162.el4rh). Thanks ...

Use C++ with Objective-C in XCode

I want to use/reuse C++ object with Objective-C. I have a hello.h that has the class definition, and hello.cpp for class implementation. class Hello { int getX() ... }; And I use this class in Objective-C function. #include "hello.h" ... - (IBAction) adderTwo:(id)sender { Hello *hi = new Hello(); int value = hi->g...

Calling another process from python/child process need to access shell

Hi, I'm calling a C/C++ program from python with Popen, python code should observe behavior of child process and collect some data for his own work. Problem is that C code already uses pipes for calling some shell commands - so after my execution from python, C program cannot execute bash shell command. Is there any way in calling fro...

What is the fastest way to compute sin and cos together?

I would like to compute both the sine and co-sine of a value together (for example to create a rotation matrix). Of course I could compute them separately one after another like a = cos(x); b = sin(x);, but I wonder if there is a faster way when needing both values. Edit: To summarize the answers so far: Vlad said, that there is the a...

How to detect segmentation fault details using Valgrind?

Hi all I have a std::map< std::string, std::string> which initialized with some API call. When I'm trying to use this map I'm getting segmentation fault. How can I detect invalid code or what is invalid or any detail which can help me to fix problem? Code looks like this: std::map< std::string, std::string> cont; some_func( cont ); //...

identifying the type

Hi, In my application, there is a inheritance hierarchy in which only the classes that are at the end of the inheritance chain are non-abstract classes. Also there is some usage of boost::variant. I want to write a function which takes a pointer and a Type and says whether the object belongs to that type. For example #define IsA(nod...

string in c++,question

Hi, I created a program in C++ that remove commas (') from a given integer. i.e. 2,00,00 would return 20000. I am not using any new space. Here is the program i created void removeCommas(string& str1,int len) { int j=0; for(int i=0;i<len;i++) { if(str1[i] == ',') continue; else { str1[j] =str1[i]; j+...

MOC adding namespace to class names

I have this very strange problem while compiling the project. MOC seems to be adding a namespace to the class name being moc'ed, although it's not mentioned anywhere in the file/class. The namespace, however, exists in a library which I use, but it's hidden far away in the header files and I don't use it in the UI files. This is what ...

C++ constructor behavior

I'm declaring an instance of a class like so: Matrix m; This appears to implicitly initialize m (i.e. run the constructor). Is this actually the case? ...

how do I initialize a float to its max/min value?

How do I hard code an absolute maximum or minimum value for a float or double? I want to search out the max/min of an array by simply iterating through and catching the largest. There are also positive and negative infinity for floats, should I use those instead? If so, how do I denote that in my code? ...

How can you animate a sprite in SFML (C++)

Lets say I have 4 images and I want to use these 4 images to animate a character. The 4 images represent the character walking. I want the animation to repeat itself as long as I press the key to move but to stop right when I unpress it. It doesn't need to be SFML specific if you don't know it, just basic theory would really help me....

How can I modify the value of a string defined in a struct?

Hi, Based on your comments, let me modified the original question... I want to create a struct with size of 4kb (this size is a requirement so I have to meet it). The problem was that I couldn't modify the value of the string variable contained in the struct because the compiler throws a segmentation fault. Currently, if I use a pointe...

Context of Main function in C or C++

Does the main function we define in C or C++ run in a process or thread. If it runs in a thread, which process is responsible for spawning it ...

How to place multiple formats on the clipboard?

For example, what Wordpad did when I press "Ctrl+C"? It places many different format to clipboard. So Notepad can get the text without any color or font...etc, and you still can keep the original format when you paste in another Wordpad window. The MSDN said I should call SetClipboardData multiple times. But it doesn't work at all. ...

Marshal a C++ class to C#

I need to access code in a native C++ DLL in some C# code but am having issues figuring out the marshaling. I've done this before with code that was straight C, but seem to have found that it's not directly possible with C++ classes. Made even more complicated by the fact that many of the classes contain virtual or inline functions. I...

How to get a flat, non-interpolated color when using vertex shaders.

Hi, Is there a way to achieve this (OpenGL 2.1)? If I draw lines like this glShadeModel(GL_FLAT); glBegin(GL_LINES); glColor3f(1.0, 1.0, 0.0); glVertex3fv(bottomLeft); glVertex3fv(topRight); glColor3f(1.0, 0.0, 0.0); glVertex3fv(topRight); glVertex3fv(topLeft); . . (draw a square) . . glEnd(); I get the desired...

Output of gcc -fdump-tree-original

If I dump the code generated by GCC for a virtual destructor (with -fdump-tree-original), I get something like this: ;; Function virtual Foo::~Foo() (null) ;; enabled by -tree-original { <<cleanup_point <<< Unknown tree: expr_stmt (void) (((struct Foo *) this)->_vptr.Foo = &_ZTV3Foo + 8) >>> >>; } <D.20148>:; if ((bool) (__in_chrg ...

g++ no matching function call error

I've got a compiler error but I can't figure out why. the .hpp: #ifndef _CGERADE_HPP #define _CGERADE_HPP #include "CVektor.hpp" #include <string> class CGerade { protected: CVektor o, rv; public: CGerade(CVektor n_o, CVektor n_rv); CVektor getPoint(float t); string toString(); }; the .cpp: #include "CGerade.hp...

Are there any high level language that don't support using C++ libraries?

Are there any high level language that don't support using C++ libraries? ...

Mapping C structure to an XML element

Suppose I have a structure in C or C++, such as: struct ConfigurableElement { int ID; char* strName; long prop1; long prop2; ... }; I would like to load/save it to/from the following XML element: <ConfigurableElement ID="1" strName="namedElem" prop1="2" prop2="3" ... /> Such a mapping can be trivially done in Java/C...