c++

How can I declare constant strings for use in both an unmanaged C++ dll and in a C# application?

Curently I'm passing my const string values up from my C++ into my C# at startup via a callback, but I'm wondering if there's a way of defining them in a C++ header file that I can then also refer to in C#. I already do this with enums as they are easy. I include a file in both my C++ library project (via a .h file with a pragma once at...

C/C++ full file path in assert macro

hello, I am wondering if it's possible to display full file path using the assert macro? I cannot specify full file path in compilation command, is there still a way to do it? My debug environment is linux/g++ ...

Implicit casting Integer calculation to float in C++

Is there any compiler that has a directive or a parameter to cast integer calculation to float implicitly. For example: float f = (1/3)*5; cout << f; the "f" is "0", because calculation's constants(1, 3, 10) are integer. I want to convert integer calculation with a compiler directive or parameter. I mean, I won't use explicit casting ...

C++ Perfect Number. Need some help revising.

I need some help revising this. It keeps only displaying 0s as the temp. Thank you. // A program to determine whether the input number is a perfect number // A perfect number is defined by the sum of all its positive divisors excluding itself // 28: 1+2+3+7+14 = 28. int perfect, limit, divisor; cout << "Please enter a positive intege...

C++ 64bit issue

I have the following code: tmp_data = simulated_data[index_data]; unsigned char *dem_content_buff; dem_content_buff = new unsigned char [dem_content_buff_size]; int tmp_data; unsigned long long tmp_64_data; if (!(strcmp(dems[i].GetValType(), "s32"))) { dem_content_buff[BytFldPos] = tmp_data; dem_content_buff[BytFldPos + 1] = tm...

Getting a shared pointer to a derived class when base class inherits from enable_shared_from_this

I have a class B which inherits from A which in turn derives from enabled_shared_from_this. Now, I want to get a shared pointer to B from an instance of B. shared_from_this will return shared_ptr<A>, not shared_ptr<B>. Should I use boost::static_pointer_cast here? Or is there a better way? ...

Windows development: x86 to x64 transition

Hi everybody. Are there any guidelines how to transit to x64 with as little pain as possible? Suppose, I have a windows native x86 executable written in C++. The EXE works fine by itself, but there is also DLL that is hosted by both, the former EXE and an outside x64 process. With setup like this, what parts would I need to rewrite? I...

How to set bit values which are not divided on byte boundary

Hi I have a header field of 2 bytes where first four bits are packet type and other 12 bits are for length. but i don't know how to store this values and retrieve them. I am using ms c++ for client and java for server. It is the client which has to set this values and server has to retrieve it. Thanks ...

Ignore carriage returns in scanf before data.... to keep layout of console based graphics with conio.h

I have the misfortune of having use conio.h in vc++ 6 for a college assignment, My problem is that my graphic setup is in the center of the screen... e.g. gotoxy( getcols()/2, getrows()/2); printf("Enter something"); scanf( "%d", &something ); now if someone accidentally hits enter before they enter the "something", then the cur...

How to implement a network protocol?

Here is a generic question. I'm not in search of the best answer, I'd just like you to express your favourite practices. I want to implement a network protocol in Java (but this is a rather general question, I faced the same issues in C++), this is not the first time, as I have done this before. But I think I am missing a good way to i...

c++ to vb.net , problems with callback function

I'm having a hard time here trying to find a solution for my problem. I'm trying to convert a client API funktion from C++ to VB.NET, and i think have some problems with the callback function. parts of the C++ code: typedef struct{ BYTE m_bRemoteChannel; BYTE m_bSendMode; BYTE m_nImgFormat; // =0 cif ; = 1 qcif char *m_s...

Architecture for Qt SIGNAL with subclass-specific, templated argument type

I am developing a scientific data acquisition application using Qt. Since I'm not a deep expert in Qt, I'd like some architecture advise from the community on the following problem: The application supports several hardware acquisition interfaces but I would like to provide an common API on top of those interfaces. Each interface has a...

using the boost::scoped_lock(Mutex &mx, bool initially_locked) constructor gives me errors.

Isn't there a boost::scoped_lock constructor that takes a boolean as the second parameter? I thought I had used it before. boost::scoped_lock(Mutex &mx, bool initially_locked) The documentation for scoped_lock shows the second parameters as "unspecified". Anyone know what in the @(*$ that is suppose to mean?!? the errors I get are: ...

C++ stl collections or linked lists

I'm developing a OpenGL based simulation in C++. I'm optmizing my code now and i see throughout the code the frequently use of std:list and std:vector. What is the more performatic: to continue using C++ stl data structs or a pointer based linked list? The main operation that involve std::list and std::vector is open a iterator and loop ...

Use WM_COPYDATA to send data between processes

I wish to send text between processes. I have found lots of examples of this but none that I can get working. Here is what I have so far: for the sending part: COPYDATASTRUCT CDS; CDS.dwData = 1; CDS.cbData = 8; CDS.lpData = NULL; SendMessage(hwnd, WM_COPYDATA , (WPARAM)hwnd, (LPARAM) (LPVOID) &CDS); the receiving part: case WM_COPY...

C++: Vector3 type "wall" ?

Say I have: class Vector3 { float x, y, z; ... bunch of cuntions .. static operator+(const Vector3&, const Vector3); }; Now, suppose I want to have classes: Position, Velocity, that are exactly like Vector3 (basically, I want typedef Vector3 Position; typedef Vector3 Velocity; Except, given: Position position; Vector3 v...

How could I redirect stdin (istream) in wxWidgets?

Hi, I'm trying to figure out how to redirect istream to wxwidgets. I was able to accomplish redirecting ostream, here's how (so you know what I mean): wxTextCtrl* stdoutctrl = new wxTextCtrl(...); wxStreamToTextRedirector redirect(stdoutctrl); //Redirect ostream std::cout<<"stdout -- does this work?"<<std::endl; //It worked. I'...

C++ Why is the converter constructor implicitly called?

Why is the Child class's converter constructor called in the code below? I mean, it automatically converts Base to Child via the Child converter constructor. The code below compiles, but shouldn't it not compile since I haven't provided bool Child::operator!=(Base const&)? class Base { }; class Child : public Base { public: Child() ...

gcc -finline-functions behaviour?

I'm using gcc with the -finline-functions optimization for release builds. In order to combat code bloat because I work on an embedded system I want to say don't inline particular functions. The obvious way to do this would be through function attributes ie attribute(noinline). The problem is this doesn't seem to work when I switch on...

Write a function in c that includes the following sequence of statements [Wont Compile]

There is a question in my programming languages textbook that is as follows: Write a C function that includes the following sequence of statements: x = 21; int x; x = 42; Run the program and explain the results. Rewrite the same code in C++ and Java and compare the results. I have written code, and played with i...