c++

What wrapper class in C++ should I use for automated resource management?

I'm a C++ amateur. I'm writing some Win32 API code and there are handles and weirdly compositely allocated objects aplenty. So I was wondering - is there some wrapper class that would make resource management easier? For example, when I want to load some data I open a file with CreateFile() and get a HANDLE. When I'm done with it, I sho...

Polynomial division overloading operator (solved)

Ok. here's the operations i successfully code so far thank's to your help: Adittion: polinom operator+(const polinom& P) const { polinom Result; constIter i = poly.begin(), j = P.poly.begin(); while (i != poly.end() && j != P.poly.end()) { //logic while both iterators are valid if (i->pow > j->pow) { //if the cu...

Managed c++ std::string not accessible in unmanaged c++

In unmanaged c++ dll i have a function which takes constant std::string as argument Prototype : void read ( const std::string &imageSpec_ ) I call this function from managed c++ dll by passing a std::string. When i debug the unmanaged c++ code the parameter imageSpec_ shows the value correctly but does not allow me to copy that value...

shared_ptr requires complete type; cannot use it with lua_State*

Hello! I'm writing a C++/OOP wrapper for Lua. My code is: class LuaState { boost::shared_ptr<lua_State> L; LuaState(): L( luaL_newstate(), LuaState::CustomDeleter ) { } } The problem is lua_State is incomplete type and shared_ptr constructor requires complete type. And I need safe pointer sharing. (Funny thing bo...

How to fetch output when calling R using Qprocess or system

Hi Experts, I would like to execute a R script simply as R --file=x.R It runs well on the command line. However when I try the system call in C++ by QProcess::execute("R --file=x.R"); or system("R --file=x.R"); the program R runs and quits but I can't see the output the program is supposed to generate. If a program uses no std...

C# wrapper of c++ dll; "Run-Time Check Failure #0 - The value of ESP was not properly saved across a function call." error

Here is the code in C++ dll: extern "C" _declspec(dllexport) int testDelegate(int (*addFunction)(int, int), int a, int b) { int res = addFunction(a, b); return res; } and here is the code in C#: public delegate int AddIntegersDelegate(int number1, int number2); public static int AddIntegers(int a, int b) { return a + b; } ...

How does one paint the entire row's background in a QStyledItemDelegate ?

I have a QTableView which I am setting a custom QStyledItemDelegate on. In addition to the custom item painting, I want to style the row's background color for the selection/hovered states. The look I am going for is something like this KGet screenshot: Here is my code: void MyDelegate::paint( QPainter* painter, const QStyleOptionVie...

What is the "munch"? How it was used with cfront

Hello What was the munch library (or program?) from cfront package? What is was used for ? Thanks ...

Visual Studio compile "filter" as C and "filters" groups as C++

Hello, I have written the majority of my project in C++. However there are several "filters" or folders which need to be compiled as C and linked to the project. How can I configure this within VStudio? Thanks. ...

Visual C++.NET , speed optimizations

Hello, I want my VC++ code to be executed as fast as possible. Does anybody know what I should change or set in project properties and settings? ...

How to initialize std::vector from C-style array?

What is the cheapest way to initialize a std::vector from a C-style array? Example: In the following class, I have a vector, but due to outside restrictions, the data will be passed in as C-style array: class Foo { std::vector<double> w_; public: void set_data(double* w, int len){ // how to cheaply initialize the std::vector? } ...

Links to official style guides

C++ has several types of styles: MFC, Boost, Google, etc. I would like to examine these styles and determine which one is best for my projects, but I want to read from the official style guidebook. Does anyone have an official guide that they typically use? Here are two that I found. I bet there are more: http://google-styleguide.g...

json to std::string in c++ from an URL.

Hello all, I want to implement something where I will get an URL which will be a link to JSON db, now I need to get the json from this URL and convert it to std:string in a c++ file. Is there any easy way to do this. ...

forward declare typedef'd struct

I can't figure out how to forward declare a windows struct. The definition is typedef struct _CONTEXT { .... } CONTEXT, *PCONTEXT I really don't want to pull into this header, as it gets included everywhere. I've tried struct CONTEXT and struct _CONTEXT with no luck (redefinition of basic types with the actuall struct in winn...

how to send classes defined in .proto (protocol-buffers) over a socket

Hi, I am trying to send a proto over a socket, but i am getting segmentation error. Could someone please help and tell me what is wrong with this example? file.proto message data{ required string x1 = 1; required uint32 x2 = 2; required float x3 = 3; } xxx.cpp ... data data_snd, data_rec; //sending data ...

Concise (yet still expressive) C++ syntax to invoke base class methods

I want to specifically invoke the base class method; what's the most concise way to do this? For example: class Base { public: bool operator != (Base&); }; class Child : public Base { public: bool operator != (Child& child_) { if(Base::operator!=(child_)) // Is there a more concise syntax than this? return true; /...

How to create something like Expander control in WPF using only WinAPI (ATL/WTL)?

Hi! I am newbie in English, sorry :) How to create something like Expander control in WPF using only WinAPI (ATL/WTL)? Are some experince avaliable? Thank for answers! ...

How to auto-include all headers in directory

I'm going through exercises of a C++ book. For each exercise I want to minimize the boilerplate code I have to write. I've set up my project a certain way but it doesn't seem right, and requires too many changes. Right now I have a single main.cpp file with the following: #include "e0614.h" int main() { E0614 ex; ex.solve(); } ...

Textfield - what is wxTextCtrlNameStr?

Question I'm trying to create a basic wxWidgets program with a text entry box, in the constructor there is a variable wxTextCtrlNameStr - in researching I can't seem to find wxTextCtrlNameStr? any help? Given Code documentation: wxTextCtrl(wxWindow* parent, wxWindowID id, const wxString& value = "", const wxPoint& pos = wxDefaul...

How to skip past loops in ddd (gdb)

During many, sometimes inundating, debugging sessions using DDD, I stumble upon loops. And I keep pressing next to get past it, and if there are many iterations, I just set a break point right after it, and press "continue." Is there any other way to go past loops? ...