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

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6
votes
2answers
594 views

Deploying Qt-based app on Mac OS X

I wrote a cross platform application and I distributed it successfully for Windows and Linux (and tested them on "clean" virtual systems, with no other additional software and/or libraries installed). ...
2
votes
1answer
214 views

Are there real world examples demonstrating reasonable performance improvement by using move semantics?

(I've asked a similar question on SO but unfortunately it might not be proper, so I also put here; please kindly point out if you think it's a duplicate.) I've heard many words about the move ...
0
votes
2answers
201 views

Mermaid problem (OOP) [closed]

A Mermaid is half fish and half human. It has upper human body and lower fish body. When under water its upper part swims like a human while its lower part swims like a fish. Please explain how can it ...
1
vote
4answers
757 views

Should non-interface code be hidden from the client?

I am working on a library which had several headers that are meant to only be used by the library itself. I also have a few classes and functions in headers that I do not want the client to use. For ...
-1
votes
1answer
58 views

One symbol - one meaning?

It's well known recomendations that: 1) class or function should have one responsibility 2) variable should not be reused in different contexts We can generalize this recomendations to general ...
0
votes
1answer
146 views

Estimed number of tries

Problem: The Oscar Committee wants to decide which person should get the best actor award among the given N actors.For that they decided to use a random function random_bit() which returns either 0 ...
-1
votes
1answer
230 views

Optimal movie schedule

Let's say Mr. A goes to cinema and he gets a movie schedule. There are N movies on the program today (1 < N < 50) and for every movie the time of the start and the time of the end are given in ...
7
votes
3answers
781 views

Apple eating problem

Player A and Player B play a game. On the middle of the table there is a pot full of N apples of different weights. Player A starts first and choose an apple and start eating it. Losing no time player ...
2
votes
1answer
1k views

How is C++ in QT different from the standard C++ libraries?

I want my app to be able to manipulate images and create watermarks and also needs to run on both windows and mac. Hence I've been investigating QT. Does QT ship with all the libraries I will need to ...
1
vote
0answers
93 views

Is the behaviour of floating-point arithmetic defined by the c++ standard?

I started writing this as a SO question but I think it's better suited here. While I'm happy for simply an answer I'm also fond of the "Teach a Man to Fish" phylosophy so I'm happy for people to point ...
0
votes
1answer
474 views

Reading a character from a file stream in c++ (AKA: Why no C++ standard equivalent of old conio.h)?

This is a question of about design decisions. I find that there are so many different things I work on where reading a _kbhit() is amazingly useful but I can't find (read: there isn't) any ...
16
votes
8answers
1k views

How to spread awareness for generic programming among team members?

I am staying in an environment, where people believe: Java generics are the feature exclusively used for library writing and not for the real coding. C++ is an OO programming language; template is ...
33
votes
17answers
7k views

Teaching C++ to first time high school students: Where to draw the line?

I will be mentoring a team of high school students for the FIRST Robotics Competition, most teams here develop[ their robot software using C++. For many of the students on the team this will be their ...
3
votes
2answers
288 views

How to iterate through all permutations of valid links between nodes

Imagine a 2D area, with a number (array) of nodes (or points) defined within it, in arbitrary (but known) positions (integer x,y coordinates), like this: From there I want to be able to, ...
1
vote
1answer
88 views

Run a c++ program under lots of different data maps

I want to run a c++ program to process a lot of data from different xml files and output results. I run the program once per file and potentially have around 50 different files. The trouble is each ...
3
votes
2answers
425 views

Transforming XML to JSON in C++ [closed]

Working with XML in C++ seems a bit of a pain and I'm looking at a way to output JSON. I've stumbled on two different approaches: A) XSLT transformations: ...
0
votes
1answer
164 views

Moving from C++ to NodeJS - Working with XML and JSON

I need to make a program to compare several large +100MB XML files, find the difference, and spit out JSON. I have written the comparison code in C++ and it performs great but now when I am getting to ...
2
votes
1answer
92 views

How minor of a case is a class appropriate for?

I'm trying to use composition in an Entity class of mine. So far, an Entity "is" Displayable(inherited an ABC), and "has" a Position(contains a point-like class). I know I will want my Entity to ...
4
votes
2answers
183 views

Is there any harm in having classes made up mostly of inherited classes?

Say I have a few base classes: HasPosition supplies a 2D location, and methods to "move". IsDisplayable defines how a class will be displayed in a given graphics library (say, curses), and methods ...
18
votes
8answers
1k views

Is directly using Make considered obsolete?

So I have been coming across many comments/posts/etc regarding creating makefiles directly, and how it is a silly thing to do in 2015. I am aware of tools such as CMake, and I actually use CMake quite ...
5
votes
2answers
306 views

Designing exception classes

I'm coding a small library and I'm having some trouble with designing the exception handling. I must say that I am (still) confused by this feature of the C++ language and I tried to read as much as ...
1
vote
5answers
1k views

How to share memory between applications written in C/C++

I'm going through a program written in C/C++ for control in robotics. Basically, three different programs run at the same time, and they communicate via shared memory. Google-ling around I found ...
11
votes
8answers
9k views

c style casts or c++ style casts

So, what do you use? int anInt = (int)aFloat; or int anInt = static_cast<int>(aFloat); // and its brethren And, more importantly, why?
2
votes
3answers
290 views

Repetitive code over multiple classes. Best way to centralize code?

I'm working with 3D arrays that I flatten into a 1D arrays with the following index calculation: index = x + WIDTH * (y + DEPTH * z) I'm starting to notice that I'm using the calculation all over ...
49
votes
13answers
3k views

Philosophy behind Undefined Behavior

C\C++ specifications leave out a large number of behaviors open for compilers to implement in their own way. There are a number of questions that always keep getting asked here about the same and we ...
0
votes
0answers
72 views

Matching groups of similar lines on a generic matching algorithm

I have to write a program to search through a file containing lines and find lines that match to a degree of tolerance but are not necessarily the same. So for example the following lines would match: ...
3
votes
3answers
382 views

No exceptions C++ and partially constructed objects

Looking over Joint Strike Fighter Air Vehicle C++ Coding Standard, rule AV 73 states something on the lines: Default c++ constructors should be avoided if that means leaving object in a partially ...
2
votes
1answer
240 views

How can C++ make it possible to use dynamic container classes even in embedded systems?

How can C++ make it possible to use dynamic container classes even in embedded systems? Background info: I've been working with PIC (C) and AVR (C++) processors and at the moment (PIC C) I'm ...
3
votes
3answers
378 views

Where should I place a typedef when used in method signatures in C++?

I'm using an Optional class quite similar to that of boost. For semantic reasons, I switched an attribute of the same (structured) type in some class definitions (and therefore also in method ...
0
votes
4answers
237 views

Fixing class Hierarchy design mistakes due to incorrect inheritance

I have a code like this. My derived class man, may not properly have a member function declared pure virtual higher up the hierarchy. eg. WagTail here class mammal{ public: virtual void WagTail() ...
4
votes
4answers
183 views

Design question concerning proper and practical encapsulation

I have been working on refactoring old code and found a lot of instances of the following type of situation: There is a master object which we call "Application" and there is only one of these. The ...
3
votes
2answers
182 views

What kind of base for Decorator: interface, abstract class, non-abstract

What should be at the top of inheritance tree of Decorator design pattern? I mean the base for both components and decorators non-abstract class: has data fields, implements methods abstract class: ...
-3
votes
2answers
154 views

How to visualise this data model?

I have learnt different variants of list data model like Dlist, SList and recursivenodetype-list. But I could not understand/visualise this datamodel as mentioned below in C++ syntax, with an ...
1
vote
1answer
201 views

how can i make a program written in c++ with qt to text and graphic mode?

I have seen in many programs, almost only on linux, that when you run the program with a graphical manager(Clicking the executable) the program runs in a graphical window and when you run it from the ...
5
votes
5answers
3k views

Is it better to use preprocessor directive or if(constant) statement?

Let's say we have a codebase that is used for many different costumers, and we have some code in it that is relevant only for costumers of type X. Is it better to use preprocessor directives to ...
2
votes
2answers
80 views

Optional Member Data

I am creating a strong binding of an XML specification and I am essentially trying to "flatten" the specification as much as possible, so that it won't feel like you are manipulating an XML tree. ...
17
votes
4answers
2k views

Debugging memory corruption

First off, I do realize this is not a perfect q&a style question with an absolute answer, but I can't think of any wording to make it work better. I don't think there is an absolute solution to ...
16
votes
5answers
3k views

Do enums create brittle interfaces?

Consider the example below. Any change to the ColorChoice enum affects all IWindowColor subclasses. Do enums tend to cause brittle interfaces? Is there something better than an enum to allow for ...
27
votes
4answers
16k views

Using scoped enums for bit flags in C++

An enum X : int (C#) or enum class X : int (C++11) is a type that has a hidden inner field of int that can hold any value. In addition, a number of predefined constants of X are defined on the enum. ...
1
vote
1answer
129 views

Experiences with C++ Async/actor model Library [closed]

I am fairly experienced with async and concurrent programming in c# using event, actor, and task based patterns, but now I have a task in c++ with which I have basic familiarity and it needs some ...
3
votes
3answers
347 views

in C++, how to call an 'init' routine as a class is loaded?

I have a program that loads a bunch of "addons" (different meters that measure and display system values). The "addons" have "grown" over time and the code of what addons to "activate", and how many ...
3
votes
4answers
10k views

how to nicely use constant std::string in c++

In my current code project, there is an awful lot of constant strings I use to print out error messages. Hardcoding such strings is generally considered to be bad practice. Now I'm searching for a ...
-1
votes
3answers
142 views

Java and C++ connection? [closed]

Quick question about them. Are they semantic kind of way related? I am learning C++ and I want to start java too. Can I get confused when learning the two languages?
0
votes
1answer
149 views

Best algorithm for “ACM ICPC Team”

I have this problem (complete description): There is a list of persons N and M topics. I have to find out the maximum number of topics a 2-person team can know. And also find out how many teams can ...
-2
votes
3answers
299 views

Programming in Linux (C++) [closed]

So I don't know If this is the right place to ask this. I am new to programming, I am not very in to it (I know classes,arrays,functions..etc(Basic Things)). I was programming with Visual Studio 2013 ...
17
votes
4answers
3k views

Why aren't `void *`'s implicitly cast in C++?

In C, there is no need to cast a void * to any other pointer type, it is always safely promoted. However, in C++, this is not the case. E.g., int *a = malloc(sizeof(int)); works in C, but not in ...
5
votes
3answers
624 views

How to make support for bindings for a scripting language

Main I'm making a scripting language using C++. I plan to use it with a simple test game editor. But I have to make a support for bindings to call game engine's nodes' methods to update positions, ...
-3
votes
1answer
235 views

Physics/Game Engine in C++ for mobile app [closed]

First post so be gentle. I am a junior seeking a Comp Sci major and was looking into making a mobile game. I wanted to use this for my thesis project next year, and possibly a way to pay back college ...
58
votes
11answers
11k views

A modern review of Java [closed]

I've been programming for a few years and I began in Java, and in my time I've found many different sources claiming Java to be an inferior language in some way or another. I'm well aware that each ...
1
vote
1answer
143 views

Avoiding std::forward and Rvalue References

I recently read the Google C++ Style Guide and especially one part catched my eye. The part about Rvalue References discourages from using std::forward in general and using rvalue references in other ...