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

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0
votes
1answer
138 views

Const and non-const methods, and possible mutable data member?

I'm working on a design and implementation change due to a bug. The bug fix requires us to modify a class object in a const method. I think the two options are: Have the non-const method cast this ...
6
votes
2answers
2k views

What is the difference between function() and function(void)?

I have heard that it is a good practice to write functions that do not receive anything as a parameter like this: int func(void); But I hear that the right way to express that is like this: int ...
1
vote
0answers
198 views

Best software architecture for an efficient network tunneling in C++

Before jumping to my questions, let me explain my project's background. I am part of a team that organize the network of a famous LAN event. Most of the games nowadays actually don't run locally but ...
0
votes
1answer
469 views

pthread versus boost::thread - need to set the thread priority on an ubuntu box

I wrote a class that basically executes a numerical analysis code in a thread using boost::thread. Now I need to specify the thread priority, since we are running a system with near real-time ...
0
votes
2answers
140 views

Usage of objects in multiple containers in C++

In cases where there is a desire for objects to be "shared" between multiple containers, I would like to know what is the best practice in C++. For example, when implementing some path algorithms ...
0
votes
0answers
50 views

Mocking delegate constructors

I am new to Unit Testing in C++. I am supposed to write a Unit test for my code and I am using Google Mock for the same. I have gone through their turtle example. But I am still confused as to how to ...
2
votes
1answer
210 views

C Module - Where to put prototypes and definitions that do not belong to the public interface?

Since I am mainly an Electrical Engineer, forgive me if I am somewhat off with some terminology. I am currently programming a display driver/interface module. And like so many times before, I have ...
2
votes
5answers
490 views

std::vector Non-Array Implementation?

I've seen some posts on the StackExchange family of sites talking about std::vector implementations. They all seem to indicate that std::vector is implemented strictly as an array (in practice), and ...
-1
votes
1answer
254 views

Are ANSI* Escape Sequences Proper For Coloring Text in Terminal(Linux)?

I just switched back to Linux after a few years of Windows use and am wondering if ANSI Escape Sequences are okay for coloring text. I ask because the way I did it on windows isn't capable of crossing ...
0
votes
2answers
158 views

Flat files for events and alarms

So I'm working on a project that I was introduced to a year ago. One of the features of project involves alarming the users when certain events are triggered. There is also a log of these events. ...
1
vote
1answer
157 views

Best solution to switch between new and deprecated code

We have a feature that is currently implemented, let's call it implA. ImplA works but can't do many things. So we have decided to rewrite it. But we can't just replace it right away, so we will need ...
3
votes
2answers
201 views

How can I have objects interacting and communicating with each other without forcing a hierarchy?

I hope these ramblings will make my question clear — I'd totally understand if they wont, though, so let me know if that's the case, and I'll try making myself clearer. Meet BoxPong, a very ...
1
vote
4answers
1k views

const reference and const pointer. How do they work?

I read a post about how const storage works. How does const storage work? (Item 2, Scott Myers Effective C++) This says that each segment has separate section of write protected memory and const ...
2
votes
2answers
485 views

Blocking function call with asynchronous content

I am sure that this is a common design pattern, but I seem to have a blind-spot. I have a requirement that the function call from Application to Service be blocking, but service needs to do ...
18
votes
8answers
6k views

When NOT to use virtual destructors?

I believed I searched many times about virtual destructors, most mention the purpose of virtual destructors, and why you need virtual destructors. Also I think in most cases destructors need to be ...
0
votes
0answers
101 views

Member vs free function [duplicate]

I've read similiar topics and also the following great article: http://www.gotw.ca/publications/mill02.htm I'm still not quite sure how to apply it though. Basically I have a class that is an ...
27
votes
1answer
2k views

Why does C++ not have a “pure” keyword for virtual functions?

I have always wondered why we code virtual void MyFunction() = 0; and not pure virtual void MyFunction(); Is there a reference for the basis of this decision?
3
votes
3answers
223 views

Is this a good method to create class hierarchies?

Is it a good design to store the type of the object in the base class as an enum? For example, consider the following hierarchy Expr --Unary --Binary --Const ----Int ----Float How to represent the ...
2
votes
2answers
1k views

Is there any advantage to c-style bit manipulation over std::bitset?

I work almost exclusively in c++11/14, and usually cringe when I see code like this: std::int64_t mArray; mArray |= someMask << 1; This is just an example; I'm talking about bit-wise ...
0
votes
3answers
271 views

What arguments are there to use a coding style for each distinct language? [duplicate]

I recently had a discussion about our coding style for C# projects. Two things in particular were very hard to agree upon. Method Naming C# has the de-facto standard of naming (at least public, ...
2
votes
1answer
154 views

Does the LGPL apply if I rewrite a portion of JasperReports in C++?

I would like to rewrite a portion of the JasperReports library in C++. The library will read from the same XML format used by JasperReports. If I integrate this C++ library to my proprietary ...
0
votes
3answers
476 views

Is there a use for non-const reference parameters?

Given a function like: void do_stuff( Thing & thing ) { // at this point, I can inadvertently or purposefully change thing } Is there a reason to purposefully change thing? Changing thing ...
0
votes
2answers
99 views

Should I set values using the return or by giving a reference?

Suppose I have a mouse position watcher, which should let the user extract the mouse position. Should the mouse position be set in the method and returned: Mouse_Position ...
3
votes
1answer
329 views

In C++, why does the main function use 'char *argv[]'?

I was wondering why C++ uses the following function prototype for the main() function: int main(int argc, char *argv[]); instead of something like: int main(std::vector<std::string> argv); ...
1
vote
1answer
103 views

A little confused with virtual functions

Please see the following code: #include<iostream.h> #include<string.h> class father { char fname[20]; public: father() { strcpy(fname,"eshwarappa"); ...
0
votes
0answers
101 views

data structure with best match lookup

Let me explain my question with one example: I have the following structs: struct Box{ unsigned char color; unsigned double width; unsigned double height; unsigned double weight; }; struct ...
0
votes
1answer
65 views

How Do I Create A Module* For A Class That Relies On Another Module?

*I'm using "Module" to mean some extension of a class, either through inheritance or composition. Say I have one of the following declarations of an Entity: using EUnit = int; class Entity : /*With ...
2
votes
1answer
154 views

C++: Make classes immutable or compatible with STL containers

Making types immutable is often desireable, especially for multi-threaded applications. There's no need to worry about concurrent access and no need for any synchronization. The common STL containers ...
1
vote
2answers
161 views

“Sweep” a vector of pointers

I'm using a vector to store pointers to objects. In some cases I destroy one or more of these objects (setting the vector spaces to NULL after each delete call), which are externally selected: for ...
1
vote
1answer
336 views

AST processing and usefulness of visitor pattern

I know the visitor pattern is typically used to traverse a hierarchy of heterogeneous objects (inheriting a same abstract object) and dissociate the processing of these objects from the data within ...
2
votes
2answers
572 views

When and why should a destructor be declared as virtual?

As in class TestA { TestA(); virtual ~TestA(); } So why and when should the destructor for TestA be virtual??
3
votes
1answer
272 views

Including standard library headers only once across multiple program headers

I am writing a program with multiple headers and code files, as so: message.h message.cpp option.h option.cpp main.cpp message.h includes option.h as message.cpp requires the definition of the ...
2
votes
1answer
247 views

Refactoring code with just a few lines different

I have two for loops in a function which look like these: for (int i=0; i < MAX; ++i) { identical_lines identical_lines identical_lines first_for_specific_line identical_lines ...
1
vote
2answers
495 views

Is returning a reference to inside a private vector bad practice?

I have the following trimmed class: #include <vector> #include "Tile.h" class Board { std::vector<Tile> boardArr; // VVV Bad Practice? Safe? Tile& getTileAt(unsigned ...
2
votes
2answers
320 views

Alternative to using getters/setters in a simple class

I'm writing a minesweeper game with curses. To represent each tile, I wrote small Tile class that contains information about the possible state of each tile (whether or not it's flagged, whether or ...
4
votes
1answer
492 views

How does modulus work?

I am not asking asking how the mathematical concept of modulus works, or how 20 % 3 == 2 I understand this fine. I'm more curious how the compiler/interpreter determines this. I can think of a very ...
0
votes
2answers
150 views

Style question: To use overloaded version or not?

Let's say I had an operator() overload that made temp_.matrix[k][j] and temp_(k+1, j+1) equivalent. In my class functions (where matrix belongs), would it be better to have if (temp_.matrix[k][j] == ...
4
votes
4answers
468 views

What makes a program (in a language like C++) cross-platform or not?

I have fairly basic programming experience with Java and I've tried C++ and Python. While it makes sense for Java, the basic programs I've written in C++ have run just fine on Windows and OS X. I've ...
0
votes
0answers
86 views

Difficulty designing my EventHandler class that uses a callback to handle key-presses

I wrote an EventHandler class that takes a std::function<void(char)>, and a std::vector<char> of chars (representing keys). If a key in the vector is pressed, the call-back is executed ...
0
votes
3answers
547 views

Compile-time vs. run-time configuration

I'm starting new project and need to decide on how to handle configuration. I recently run into suckless project. While it has its own issues, I really liked its approach to configuration - just a ...
6
votes
2answers
274 views

Static console object or dependency injection?

For a current project I have created a Console class which wraps up C++'s usual cout, writes output to a file or uses Console::WriteLine depending on the environment. Currently I've setup my code base ...
3
votes
1answer
393 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
212 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 ...
2
votes
3answers
672 views

In C++, should I ever declare a local variable in the corresponding header?

So for example, I create a class with two functions: foo.h class foo { public: foo(); void bar(); void ey(); bool m_memberBool; bool localBool; // ??? Should I put this here? }; ...
-1
votes
1answer
66 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 ...
6
votes
8answers
1k views

Structuring Procedural vs OO code

I have spent the vast majority of my programming career using Java and very OO based C++. I am really interested in learning to think more procedurally, so I have been starting to do some practice ...
3
votes
1answer
200 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 a simple answer I'm also fond of the "Teach a Man to Fish" philosophy so I'm happy for people to point ...
0
votes
1answer
204 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 ...
1
vote
1answer
94 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 ...
2
votes
1answer
93 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 ...