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

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0
votes
1answer
432 views

Interface questions for using Command Pattern and Dependency Injection together

I have many projects that have essentially the same high level requirement: test all hardware on a device. Each device can have a different communication protocol, requires different test equipment to ...
3
votes
1answer
128 views

How can I use the “Non-Member Functions Improve Encapsulation” pattern from C#?

In 2000, Scott Meyers argued that non-member functions improve encapsulation. In C++, a non-member function is a C-style global function: ...
0
votes
1answer
67 views

C++ Templates where the type is a shared_ptr

When creating template classes in C++, if the type upon which the template will be specialized is intended to be a shared_ptr type, is it better to make T a shared_ptr type or make T a non-pointer ...
0
votes
2answers
102 views

Organizing C++ Components [closed]

In my current company we've brought the discussion about how to organize most of our different C++ components considering the following requirements: There might be interdependencies between ...
2
votes
1answer
167 views

An embedded C developer wishing to interface some code with a web page

Okay, so as the title says, I'm an embedded C/C++ developer. Right now, I'm working on a project that involves a client/server C application. The server side of the application is running on ...
-1
votes
5answers
1k views

Why Java is a factor 2-3 slower than equivalent C++ program? [closed]

I know there is an opinion that programs written in Java and running under JVM as as fast as C++ programs, after introducing just-in-time (JIT). I see many cases when Java is terribly slow for simple ...
0
votes
1answer
100 views

Is it not direct usage of primitive pointer types form of Primitive Obsession?

Using primitive data types to represent domain ideas is code smell called Primitive Obsession. For example using string data type to represent human name - it is recomended to avoid this by defining ...
4
votes
3answers
147 views

Enforcing manual inclusion of a specific header file (banned.h)

Banned.h is a list of ANSI C functions that Microsoft is trying to persuade programmers to deprecate. I already know how to enforce automatic inclusion of banned.h (such as the answer to Ensuring that ...
75
votes
7answers
61k views

When do you use float and when do you use double

Frequently in my programming experience I need to make a decision whether I should use float or double for my real numbers. Sometimes I go for float, sometimes I go for double, but really this feels ...
1
vote
1answer
53 views

Should factory make context or concrete strategies objects in strategy-factory pattern?

In a typical strategy pattern class Strategy { public: virtual int execute() const = 0; } class StrategyA : public Strategy { public: int execute() const override; } class StrategyB : ...
2
votes
1answer
168 views

Well defined mathematical operations for bearing (angle) class

I have written a class to represent bearings (angles with a nautical theme, and a specific normalisation range). In the program, it is necessary to perform some mathematical operations on them, so ...
1
vote
2answers
114 views

saving connectivity information in a nodes/edges network

I want to implement the A* algorithm. I have a network with Nodes and Edges, both are classes. Now, I am unsure how to approach the connectivity information. Should a node know which edges depart ...
1
vote
1answer
178 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
0answers
70 views

How to avoid default member construction? [migrated]

I`m implementing move constructor and operator= for my class and I wish to implement moving only once inside operator=(). But member object constructed constructed before constructor body executes and ...
-1
votes
0answers
19 views

Shortcomings in the program (Linked Lists: Deletion and Searching) [migrated]

The following pseudo-code deletes a node from the linked list. void list::erase()//Deletes a node { cout<< "Enter a position: "; cin>> pos; if(pos==1) { current=head; ...
0
votes
0answers
116 views

General design choices. How do you decide?

I have a project in C that I'm looking to convert to C++. The project does white box hardware testing of a device (actually many similar devices). In this case the device has two processors. Each ...
23
votes
8answers
10k views

Is Learning C++ Through The Qt Framework Really Learning C++ [closed]

The problem I have, is that most of the C++ books I read spend almost forever on syntax and the basics of the language, e.g. for and loops while, arrays, lists, pointers, etc. But they never seem to ...
10
votes
5answers
843 views

How to migrate my thinking from C++ to C#

I am an experienced C++ developer, I know the language in great details and have used some of its specific features intensively. Also, I know principles of OOD and design patterns. I am now learning ...
0
votes
0answers
5 views

Why can't we use std::fill() the same way for 1D and 2D arrays? [migrated]

I have seen that if we have a 1D array int A[10], then to fill it with an arbitrary value, say 0, we use std::fill(A, A+10, 0) For a 2D array B[10][10], we fill it with 0 as: ...
0
votes
0answers
85 views

Why C++ STL vector does not go out of range [migrated]

I have this code and I am wondering how it works; Why does it allow me to access an element using a value larger than the size of the vector using the operator[]? But then when I use the at() ...
7
votes
4answers
564 views

How to prevent others from using non-thread safe variables in a multithreading environment?

I have an application written in C++ that was originally single threaded, but, due to the increasing complexity of this project, I'll need to expand it to at least two or three threads. There are ...
2
votes
0answers
80 views

Forcing Opengl 2.0 and above in c++ [migrated]

I am a student learning c++ and opengl for 5 months now and we have touched some advanced topics over the course of time starting from basic opengl like glBegin/glEnd to VA to VBO to shaders etc. Our ...
-4
votes
0answers
52 views

Why 1 bytes has 8 bits? [duplicate]

Past time Latin language was used in computer for giving command ,Latin language has 256 characters,for represent 256 word 8 bits was used . 2^8=256 8 bits are enough for representing 256 character . ...
2
votes
1answer
209 views

Tips for understanding big project fast? [duplicate]

I've got a job and many new things to be learned. The first thing is to understand big project, writtened mostly in C++, using Visual Studio. So, I see a statement, and I want to find its definition. ...
0
votes
0answers
4 views

From data file to Multi-Dimensional vector problems [migrated]

I am trying to write a "text adventure" engine that runs off of text and data files. I understand the concepts of arrays and multidimensional arrays, but know they cause memory leaks and not ...
11
votes
7answers
15k views

What is the point of using lists over vectors, in C++?

I've run 3 different experiments involving C++ lists and vectors. Those with vectors proved more efficient, even when a lot of insertions in the middle were involved. Hence the question: in which ...
0
votes
2answers
1k views

efficient way to count number of swaps in insertion sort

I am browsing some online coding challenge online and got struck somewhere . Objective of program is to find maximum number of swaps required in sorting an array via insertion sort in efficient time ...
0
votes
1answer
102 views

How shall I handle event loop exceptions?

What is the best practice for handling exceptions thrown from event handlers/listeners in a event loop? For example: class EventLoop { public: void start(); //create a thread which calls run(); ...
1
vote
2answers
155 views

Why does this implementation of Dijkstra's algorithm work in O(n^2)?

Here is the code I use for implementing Dijkstra's algorithm. Consider a graph with n vertices and m edges. Shouldn't it run in O(n^2 m) ? Someone may say that there are n vertices and each edge gets ...
1
vote
1answer
176 views

Why does this algorithm work in O(n m)?

This is from a blog post on Codeforces. I couldn't really understand why the editorialist goes on to claim that this code works in O(n m) This is a graph problem, where we are supposed to find the ...
12
votes
3answers
398 views

What is the point of making a syntactic distinction between standard and user-defined types?

Although here I will refer specifically to C++ and Bjarne Stroustrup's naming conventions, in principle, I've seen that people use somewhat similar rules for other languages here and there. So, the ...
1
vote
1answer
137 views

C++ Template Metaprogramming and Call By Need Evaluation

I recently wrote a fairly complex C++ meta function that boils down to: template <size_t N, typename val> struct Rec { using type = typename std::conditional<N == 0, val, ...
-3
votes
1answer
242 views

If-else in C++ Programming Language [closed]

I am a little bit confused about this code. Why does the else block get executed? Please explain it. int a=10,b=20; char x=1,y=0; if(a,b,x,y){ cout << "A" << endl; }else{ cout ...
2
votes
1answer
151 views

Genetic Algorithm's Tournament Selection limit to be selected

I started working again on a Genetic Algorithm and i'm trying a lot of operators and ways of selection. When I made the Tournament Selection , I noticed that it gets really easy to always get the top ...
1
vote
1answer
172 views

Using streams to connect programming languages

I'm trying to run a computation-heavy program that creates an image on a website. Is it possible to compute in C++ and have an output stream that connects to an input stream in Node.js to display an ...
1
vote
0answers
58 views

Maximizing reuse out of a function primitive in CUDA

I'm working on the implementation of a few related algorithms in CUDA, all of which require a primitive that we'll call f(). The related algorithms can't simply call f though, as they require f to ...
4
votes
3answers
1k views

Injecting dependencies (DI) in c++ applications

I am playing with dependency injection, but i am not sure I am doing it right. Especially, I am not sure what should be the correct way to build classes with injected dependencies. Say I have a class ...
23
votes
8answers
11k views

Why was Scala not implemented with C or C++

Does anybody know why was Scala implemented in Java and .NET instead of C or C++? Most languages are implemented with Cor C++ [i.e Erlang, Python, PHP, Ruby, Perl]. What are the advantages for Scala ...
78
votes
14answers
32k views

Why are most browsers developed in C++ [closed]

It seems like most of common web browsers (Firefox, Chrome, Safari) are developed using C++. Whys is that so?
54
votes
11answers
6k views

Did the developers of Java consciously abandon RAII?

As a long-time C# programmer, I have recently come to learn more about the advantages of Resource Acquisition Is Initialization (RAII). In particular, I have discovered that the C# idiom: using (var ...
2
votes
1answer
162 views

Insertion sorting Algorithm comparison

I recently came across sorting techniques and of particular, 'insertion sorting'. Although the logic and method is fairly understandable, the actual function seemed a bit complex (given below). ...
6
votes
2answers
10k views

How to run C++ code in browser using asm.js?

An asm.js application is very fast (near native C++ speed): http://kripken.github.io/mloc_emscripten_talk/micro4b.png But how is it possible to write one in C++, convert it to LLVM code, then do ...
3
votes
3answers
480 views

Should I try it straight or should I first check if it can be done?

I have a set of items, and each item in the set must be unique. Item are composed from multiple properties and each property of each item can be changed. But after each change every item in the set ...
8
votes
5answers
901 views

How to structure a loop that repeats until success and handles failures

I am a self-taught programmer. I started programming about 1.5 years ago. Now I have started to have programming classes in school. We have had programming classes for 1/2 year and will have another ...
21
votes
4answers
10k views

Where should I put functions that are not related to a class?

I am working on a C++ project where I have a bunch of math functions that I initially wrote to use as part of a class. As I've been writing more code, though, I've realized I need these math functions ...
4
votes
1answer
174 views

Designing interfaces to hardware

I am writing a library in C++ that is used by customers to interface with hardware. There are many different devices that I need to support. For the sake of simplicity, assume I have 2 Widgets, ...
118
votes
19answers
93k views

Is there any reason to use C++ instead of C, Perl, Python, etc.? [closed]

As a Linux (server side) developer, I don't know where and why should I use C++. When I'm going for performance, the first and last choice is C. When "performance" isn't the main issue, programming ...
4
votes
1answer
276 views

What is the status of @ and $ characters in C++?

C++ syntax uses almost all printable ASCII characters and some of them in several contexts. Only two unused are @ and $ characters. Why they are not used? Are they reserved for some "meta" purpose?
3
votes
4answers
400 views

Are `switch` statements generally used wrong? [closed]

I see most developers using switch statements with breaks in each and every case. Is this usage of switch statements inappropriate since a simple set of if-else statements would suffice? Is it OK for ...
3
votes
5answers
459 views

Storing a pointer to an argument passed by (non-const) reference

When designing an interface for passing objects which are meant to be stored for later use and which should not be 'null', I am always a bit uncertain if the argument should be passed by reference or ...