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

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0
votes
1answer
57 views

Perrin sequence help c++

Hey everyone I am trying to write a recursive function for a perrin sequence where it returns the nth term that a user enters which is: P(0) = 3, P(1) = 0, P(2) = 2, and P(n) = P(n − 2) + P(n − 3) ...
58
votes
11answers
8k views

Why is base-for-all-objects discouraged in C++

Stroustrup says "Don’t immediately invent a unique base for all of your classes (an Object class). Typically, you can do better without it for many/most classes." (The C++ Programming Language Fourth ...
3
votes
2answers
737 views

How do you usually compile C/C++ source code ? (Large code bases) [closed]

It's been quite some times since I began learning C and C++ but I've been very limited only to the Windows platform and the Visual Studio environment. Recently, I wanted to look into some open source ...
3
votes
1answer
201 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
132 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
113 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
213 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
2k 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
112 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 ...
1
vote
1answer
79 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
205 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
0answers
129 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 ...
2
votes
1answer
317 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
1answer
130 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
1answer
193 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 ...
1
vote
2answers
184 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 ...
-3
votes
1answer
253 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 ...
1
vote
1answer
193 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
63 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 ...
2
votes
1answer
203 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 ...
2
votes
1answer
200 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). ...
1
vote
1answer
163 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
3answers
486 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 ...
4
votes
1answer
298 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
447 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
0answers
233 views

How do you pronounce 'char' keyword? [closed]

So, with the possibility of this question being closed due to being non-productive as in the case of other pronunciation questions, I take the risk and ask it just because i have heard it said both ...
1
vote
2answers
109 views

Class as resource handle & Bad Copy

I am reading Bjarne Stroustrup's book titled "A tour of C++". The following section is confusing to me: When a class is a resource handle – that is, when the class is responsible for an object ...
-1
votes
1answer
81 views

What are some hashmaps we can easily implement? [duplicate]

At many places, I read that we can use HashMap here for O(1) search. Actually, I want to ask how I can implement easy hashmaps which can satisfy this property. Can anyone tell few hashmaps including ...
1
vote
1answer
163 views

Constructor vs casting operator

I'm programming a library (so I have complete access to all the mentioned classes). Two classes (A and B) are essentially the same and differ only by their implementation, so they can be easily ...
4
votes
1answer
184 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, ...
8
votes
5answers
1k 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 ...
9
votes
7answers
1k views

Will a profound knowledge of C++ help you in learning other languages faster/easier? [closed]

Is there a possibility that someone who has learned all the key aspects of C++ and knows the fundamentals of the language very well, will learn other languages (such as, Python, Perl, Java) faster and ...
-2
votes
2answers
488 views

What is the simplest and universal algorithm for parsing C++ code? [closed]

I need to do some project specific automatic checking of source codes written in C++ Limitations: Algorithm and its implementation should be simple, easily maintainable, extendable and ...
3
votes
2answers
256 views

Is it always safe to shift bool values?

I stumbled about a Cppcheck warning (an inconclusive one), that I mistakenly used & instead of &&: /// @param code identifies the command. Only the lower 16 bits of are being processed ...
0
votes
3answers
71 views

Defining resource allocation in method documentation

I want to write a library with "no resource leak guarantee" feature. So I shall know whether each method allocates any resource or not. It may change the code. For example: void foo() { ...
4
votes
2answers
267 views

Needs (in principle) C++ parenthesis around if statement condition?

In current C++ when body of if statements contain only one command then: Parenthesis around if condition are mandatory but block are optional. So, both examples are OK: if ( condition ) { return 0; ...
2
votes
2answers
364 views

Use of raw pointer of std::vector

I am currently maintaining a code that makes liberal use of raw pointers where std::vector would be a better option. Worse, these pointers are not always properly handled (when run using Intel ...
3
votes
2answers
184 views

How to deal with historic exception specifications in maintained C++ code

Today, I discovered a few exception specifications in legacy code I've to maintain, when Cppcheck 1.68 ([Inconclusive] but correctly) pointed out that the specified exceptions are not handled in ...
1
vote
0answers
121 views

Requesting information regarding the use of MUI vs. the use of GetText for i18n/L10n of Windows desktop applications

I have spent the past two days investigating which technology I will use to support translations of text strings (as part of an overall internationalization migration) for an archaic (VC6) Windows ...
3
votes
3answers
344 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 ...
2
votes
3answers
4k views

Efficient algorithm to count number of substrings divisible by 3

Given a string of decimal digits, I have to find the number of all substrings divisible by 3 in the range L to R [both inclusive], where L & R are index[1-based] of the specified string string ...
0
votes
1answer
83 views

Is it possible to save and load a decorated object

I am wondering if there is an easy way to save and load a decorated object in c++ as i have never done file handling in C++ before. Currently the only object type I need to save is objects that ...
2
votes
1answer
110 views

How to make max-heap stable with counter and account for counter overflow?

Generally I need size-efficient data structure similar to std::priority_queue but stable (preserving order of insertion). By adding just 4 bytes to the object I could have 1 byte serving as priority ...
1
vote
2answers
162 views

Unsure about the decorator design pattern

I'm fairly new at using design patterns and I am currently making a small game for my uni course that I have to use the decorator pattern for creating the different classes of NPC however I think that ...
24
votes
9answers
3k views

What is different between the internal design of Java and C++ that lets C++ have multiple inheritance? [duplicate]

It's drilled into the newbie Java programmers that Java (pre-Java 8) has no multiple class inheritance, and only multiple interface inheritance, because otherwise you run into diamond inheritance ...
0
votes
0answers
65 views

Mailbox Pattern with Variable Arguments in C++

In a game I'm developing, the GUI thread is catching user actions, and the simulation thread is responsible of handling and responding to them. To minimize complexity and delay, I predefined all ...
1
vote
2answers
96 views

How do you decide member objects?

So OOP is about breaking down functionality, making each class responsible for one thing etc. But let's take the example where an object is using another object. First thing that comes to mind ...
4
votes
2answers
418 views

Is the rule of 5 a valid extension of the rule of 3, or does it imply premature optimization?

I'm familiar with the notion in c++ of the rule of 3, however since the release of C++11 I've seen some sources suggesting it should be extended to a "rule of 5", I.e. the move constructor and move ...
0
votes
1answer
101 views

Passing by argument vs keeping it as a member

I really cannot decide what option is the best, I see plenty of down/upsides to both approaches and right now I'm undecided. For example; class DX11GBuffer { public: DX11GBuffer(ID3D11DevicePtr ...
0
votes
1answer
218 views

The difference between *s.pd and s->pd

I was reading about copy constructors for structs and i found this example: #include <iostream> #include <string> using namespace std; struct SomeData { int * pd; string id; ...