Questions about C++, a statically typed, free-form, multi-paradigm, compiled, general-purpose programming language.

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5
votes
3answers
399 views

Member functions vs. Non-member functions for math operators

I'm writing a linear algebra library (long story short, it's a school assignment) that involves matrices, vectors, etc. In the process of creating this library, I'm going to be creating functions ...
0
votes
2answers
333 views

How do programs like JAVA and C++ store variables in a database , does it still use MySQL like in PHP? [closed]

I imagine they have to have some sort of query to goes to a database , or maybe I'm wrong and they can just store it to their computer? Is MySQL for server - side scripting only?
0
votes
2answers
110 views

Design principles : classifying different types of class [closed]

I'm trying to clarify the design of a C++ application, and would like to define a clear classification among classes to aid clarity. However I'm struggling to find any literature to help me, probably ...
1
vote
3answers
171 views

C++ project organization to reduce unit testing build time

I want to organize tests for a project large enough that build time matters (especially for the CI server). Say I have this code that I would like to test : //foo/greet.cpp #include <stdio.h> ...
0
votes
0answers
61 views

On the process of replacing an internal framework by a public one [duplicate]

I am working on several applications which depends on a framework which was developed by a prior engineer in the company. The framework was mainly developed and maintained in the early 2000s, and ...
1
vote
1answer
376 views

Running a process multiple times at the same time

I have a c++ program with opencv library which takes an image as input and perform pose estimation,color detection,phog. When I run this program from the command line it takes around 4-5sec to ...
0
votes
0answers
29 views

Offload traces into shared memory

There is a task to trace thread execution activity for posthumous analysis with minimum impact on latency/performance. Stack trace might be not enough to understand the reason of crash. Initially I ...
1
vote
1answer
69 views

How to convey lifetime requirements?

Usually I use std::unique_ptr to convey ownership and pass in raw pointers as parameters when no ownership is implied. However, I almost never consider a nullptr to be acceptable as an argument, so it ...
1
vote
3answers
179 views

How to manage focus for a small set of simple widgets

I'm developing a set of simple widgets for a small (128x128) display. For example I'd like to have a main screen with an overlay menu which I can use to toggle visibilty of main screen elements. Each ...
2
votes
2answers
376 views

Doing work in vector's push back

I often use the following syntax: std::vector<foo> vec; vec.push_back( someClass.getFoo(...).modifyAndReturn() ); Considered about exception safety, I quote the standard on vector's push back ...
1
vote
1answer
182 views

Are there advantages to declaring stack variables constant in C++

It's not clear to me what benefits there are of declaring your stack variables as constant in C++, I was hoping somebody might explain the benefits and purpose for this technique. For example: void ...
0
votes
4answers
457 views

How does assembly relate to machine/binary code

How does assembly relate to machine/binary code. For example here is how to print to the screen in mikeOS(a small pure assembly OS), mikeOS it uses NASM to assemble. BITS 16 ORG 32768 ...
4
votes
3answers
486 views

What are my options for using a C++11 library in a C# WPF application? [closed]

I am writing a cross-platform (OS X and Windows) desktop application in C++11. I intend to use the same C++11 core on both platforms, utilizing native frameworks for the UI (Cocoa and Objective-C on ...
-1
votes
1answer
180 views

Live share prices for a side project [closed]

Me and some of my friends would want to start a side project which we will work at our spare time. Here is our criteria 1) A challenging project which will teach us skills which has business value in ...
1
vote
3answers
288 views

Choice between 1-dimensional and 2-dimensional array

I'm implementing the Chessboard class to represent the chessboard. I've to implement the transformations (reflections and rotations) on the chess board possible. The possible transformations includes ...
0
votes
1answer
111 views

How to provide a custom ID to a downloadable application?

I've noticed that with remote support services, a technician usually sends you a download link to an executable. When you click on that link, it installs a software which automatically connects with ...
1
vote
2answers
144 views

Data retrieval and indexing

I have around 800,000 rows of data stored in the boost shared memory from the database. The data are in the form: Id Color Length Size 1 1 2 ...
2
votes
2answers
235 views

Trying to get a better understanding of object-oriented design's performance pitfalls

I'm currently in a high-performance computing class taught in C++. Usually, I do work in C#, meaning everything is taken care of for me, and optimization comes behind maintainability and higher-level ...
0
votes
4answers
300 views

Binary Search seems superior, why did the committee of C++ still have Find in the algorithm library?

I wish to search for an integer in a vector of integer. I have two candidates for the job: Binary Search Find It seems that Binary Search is the best candidate for the job as although I have to ...
0
votes
1answer
139 views

Is TCP message order still guaranteed when using async IO

Here the scenario I'm imagining. Two messages are transferred, both will require 2 packets each (I know you don't deal with packets directly with TCP, but on the IP level each message will consist of ...
0
votes
2answers
346 views

How do I pass a variable's value from one class into another? (C++)

I have a class ("Class A", we'll call it) which calculates the value of a private variable (which we can call numLoaves) with a public function. I need to use the value of numLoaves in a public ...
1
vote
6answers
534 views

Coming from high-level to C [closed]

I have a web background that grants me basic understanding over programming. Some older kids wouldn't even call that programming knowledge ("any moron can do PHP/Python/Ruby"), I guess, but let's not ...
1
vote
1answer
373 views

Implementation of deque in C++ with an array

How is the end() function implemented in deque-STL of C++ with array? As per my knowledge it returns past-the-end element. But when a loop is run like, for(i=deq.begin();i!=deq.end();i++) and the ...
1
vote
2answers
293 views

Decouple GUI & Program logic

I have some windows c++ code (pure winapi c++, no MFC etc) that I would like to build a GUI for. My code does not know about windows GUI, it is completely decoupled from any type of UI. The question: ...
1
vote
2answers
114 views

Maintaining independence between modules

I am reading Algorithms 4th Edition by Robert Sedgewick and in chapter 1.2 it discusses API design. It says: "The key to success in modular programming is to maintain independence between modules. ...
-1
votes
1answer
133 views

C++ program compiles fine, but I get a number of odd errors at runtime [closed]

So I've got a little experience in java, and recently I thought it would be nice to branch into c++. I've done a little programming in it, but I still know very little about the language. Recently, I ...
1
vote
0answers
126 views

How to organize points on a sphere in bins and navigate between bins?

I'm having trouble coming up with a suitable way to navigate through a set of star coordinates in the Equatorial Coordinate System. My goal is to display those which are within a given range of ...
1
vote
2answers
180 views

Large number of projects for a single application

I'm working on 300K line C/C++ Windows application that is spread across 23 different Eclipse projects (approximately one third for Qt interface, one third for DLLs and one third for static ...
14
votes
2answers
635 views

Which is better: a bunch of getters or 1 method with a selection string parameter?

Our knowledge domain involves people walking over a pressure-recording plate with their bare feet. We do image recognition which results in objects of the 'Foot' class, if a human foot is recognized ...
2
votes
3answers
338 views

To store data or not?

I'd like to ask you about one simple thing. I have class A that do something (for example counts something ). There is also one class B that handle some parameters to this class (class A is member of ...
1
vote
2answers
217 views

How to deliver 3 different parameters to class in one method (2 of 3 are optional)

I need your help how to implement it nice and well. It's quite a simple problem. I can solve it but I need help on how to do that better. My class has logic working using three parameters. It gets ...
1
vote
3answers
2k views

C++ Performance vs. Java/C# [closed]

My understanding is that C/C++ produces native code to run on a particular machine architecture. Conversely, languages like Java and C# run on top of a virtual machine which abstracts away the native ...
1
vote
0answers
81 views

R* Tree work with dynamic data

I'm searching an algorithm to store my data (which are moving objects' coordinates) and allow me to query objects within a specific radius of a specific point. I came up with R* Tree which is said as ...
2
votes
3answers
156 views

What's the best way to retrieve a value and a status [closed]

Given that all else is equal, and there are no coding standards defining the best approach, what would be the recommended way in C++ to check that a value exists and return it if it does? For ...
0
votes
1answer
142 views

distributed computing with remote hetrogenous machines

The way i am doing it now is using boost::asio TCP sockets handling everything manually with a main server that orchestrates the processes between the available machines, but the number of machines ...
-1
votes
1answer
103 views

A Server sending data to be processed to clients [closed]

About a year ago I had an idea in mind which was using my friends computers to help me process my data, so I programmed a socket server application with boost::asio, and gave the client part of it to ...
0
votes
1answer
416 views

Good practice using signals and event driven system

I am using signals (specifically Boost signals2) to create an event driven protocol API and model. Most elements have their own signals, and there are usually multiple of each element. Consider a ...
1
vote
1answer
404 views

Is it good or bad practice to provide separate classes for an object: one to build it, and one to use it?

Suppose I'm writing some C++ code to visualize "Foo" objects. I have two ways of getting a "Foo": computing it from data, or from taking the pieces of a precomputed "Foo" and building a new "Foo". ...
2
votes
2answers
280 views

Why function returning by Address can not be a Lvalue?

Why it is not possible to make it LValue if a function return by address (while possible in case of reference)? int* returnByAdress() { int x =20; return &x; } int& ...
2
votes
1answer
243 views

Is there already a “Binder” data-structure?

I was thinking of a data structure that I cannot describe better than with the word "book", or more exactly "binder". I was wondering if this had already been implemented in libraries like Boost or ...
1
vote
3answers
553 views

How to use mock objects [C++] without passing them as arguments to functions

I'm in the process of integrating a Unit Testing Framework for an existing code base in C++. I've zeroed down on CxxTest, but as it turns out we can use other Mocking Frameworks (like googlemock) in ...
0
votes
3answers
415 views

Why are there so few comments in C/C++ code? [closed]

I'm a web developer primarily, and I've been learning C/C++ and trying to get involved in some open source projects. Something I find very unusual is the lack of comments in C/C++ source code (I've ...
4
votes
2answers
211 views

Etymology of 'virtual' (method/method table/inheritance)

As far as I know, it generally refers to late or dynamic bindng. So why a word like late or dynamic wasn't used?
-2
votes
4answers
279 views

Are for loops supposed to be read inward or outward? [closed]

for (i = 0; i < 3; i++) { for (j = 0; j < 4; j++) { cout << arr2d[i][j] << "\t"; } cout << endl; ..... Like that for example. Do you read ...
0
votes
2answers
89 views

I need advice for a subsystem design?

I'm doing it in C++, I can't post the entire thing, because it's gigantic, I'll just sum it up with a simple example.I have: class B; class A { //Members and methods... void DoSomething(B* ...
3
votes
3answers
447 views

Specifics of Switch and If statements

Why do we need the switch statement if there is the if statement? Why can't we use several ifs like if(a==1) do this1; if(a==2) do this2; ... instead of switch (a) { case(1): {do ...
22
votes
4answers
3k views

Why do C++ and Java both use the notion of “reference” but not in the same sense?

In C++ a reference argument to a function allows the function to make the reference refer to something else: int replacement = 23; void changeNumberReference(int& reference) { reference = ...
3
votes
4answers
644 views

Use null object as argument to method

Consider the following piece of code class Foo { public: //... bool valueFirstGet(int& value) const { if(this==nullptr) {return 0;} ...
9
votes
3answers
542 views

How should I mark types in C and C++ programs?

In this answer of mine, I used _t at end of types, which ended at best, controversial. This is the practice I use in my current projects. typedef struct { int x; int y; } point_t; This was ...
8
votes
3answers
1k views

Style guide for C++

Right now I am using Google C++ Style Guide in my C++ code and I was pretty happy with it. Recently I was told that this guide is very bad: it is used internally by Google (I knew that), is outdated, ...