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

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1
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2answers
176 views

Why doesn't the compiler complain when I try to access a non-existent array value?

My C++ book says that if I have int anArray[25]; and I try to evaluate anArray[25] = 0; the program will simply overwrite whatever value is stored in the next memory address past the end of the ...
0
votes
0answers
71 views

Arbitrarily sized (and signedness) integer arithmetic in C++ - How can it be done generically at runtime?

How can I efficiently handle integers of unknown size and signedness in various arithmetical operations in C++? (for a virtual machine). I am storing the program for the virtual machine in a string ...
2
votes
3answers
149 views

Adding a function to class member

I'm not sure of the proper terminology here so I'm having trouble finding the answer to my question but here is what I want to achieve. say I have class ABC { public: int number; }; and I ...
-2
votes
1answer
74 views

Static Polymorphism explained

Here is a code I have got from here: class Deletor { public: virtual ~Deletor() {} }; template<typename T> class Base : public Deletor { public: int Run() { return ...
5
votes
2answers
366 views

Why is threading platform-dependent?

I am reading book "Foundations of Qt Development", Chapter 12, and I read that threading is platform-dependent, can someone explain, why? I know how to use threads but that what they said is not so ...
2
votes
3answers
155 views

When to mark a function as virtual?

I'm trying to understand the idiomatic way to code. I'm using gmock to unit test the components I write. Gmock requires methods to be virtual to be able to mock but the class I'm trying to mock has a ...
2
votes
2answers
129 views

How to write unit tests for network client?

I need to write simple http client. It could be great to have unit tests for my class. But I don't know how to write proper and testable class. For example, I have a client like this: class ...
4
votes
3answers
127 views

How should I write an interface that takes a list of items?

I'm writing a library function that takes a list (or "bunch") of items (let's say Student) and does something with them. What's the best way to write the function signature in the interface? ...
3
votes
2answers
222 views

How to stay DRY with return values

I have a bunch of repetitive C++ code that looks like this: // Compute finalOutput if possible. Return true if successful, false otherwise // finalOutput only holds a valid value if true is returned. ...
5
votes
3answers
249 views

How aggressively to change in-house smart pointer to unique_ptr?

I work on a large software product which, being over 20 years old, has a number of constructs which have been superseded by language updates. One of these is a home-rolled smart pointer template ...
4
votes
1answer
339 views

Why double colon instead of dot?

It is rumoured that early C++ implementations have had dot operator for namespace access. There is an opinion that the dot is more convenient that the modern double colon operator. What was the ...
1
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2answers
89 views

Catching exceptions from child process

I am looking for any info. (I know some C++ with win32 and C#) The Idea: The idea is to help a program with missing files load. In the end I wanted to see if I could have my program launch a simple ...
-2
votes
3answers
180 views

Is it possible to have private or protected objects in Java? Or are all objects considered public?

Is it possible to have private objects? For example, when you instantiate an object (classType object1 = new classType()), can that be private or protected or is it always public?
0
votes
1answer
117 views

Find if certain files have been added or removed in large directory structure

I have a larger directory structure (dir + sub directories) with files. It contains files of certain types. For one particular type (let's say with appendix .foo) I need to figure out if files have ...
0
votes
1answer
97 views

How to store state data when the data is related to another entity?

In order to increase the parallel-ability of my objects, I try to make them read-only and include only data that naturally belong to the entity. I have class Object { ... }; class Processor { ...
1
vote
1answer
86 views

Client-Server app architecture with custom communication protocol

I am working on Qt/QML/C++ based Client-Server software system with custom protocol. Now, in both projects inside QtCreator I have same header and implementation files inside both projects. What is ...
0
votes
5answers
250 views

Is there a better way to debug while avoiding getters/setters?

I'm thinking about how to debug better without using Getters/Setters. If it helps, I program using xcode. Many answers in Stack Exchange have argued against Getters/Setters for lack of encapsulation ...
2
votes
2answers
441 views

Should we “balance” the amount of codes between headers and cpp?

As far as I know, cpp usually contains far more codes than headers, mainly because they contain implementation details of functions instead of just one line of function definition. Here comes to my ...
12
votes
1answer
304 views

Should I add the source of libraries instead of linking to them?

I'm relatively new to C++, so I'm not sure how I should best handle small dependencies (e.g., a scripting language, or a JSON/YAML/XML Parser). Should I create separate projects and link them as ...
8
votes
5answers
543 views

Is it correct to say that a variable is an instance of a data type?

(that can change its value over the course of the program) Or is 'instance of something' strictly related to classes and objects? If so, how would you define the concept of 'variable' when it comes ...
1
vote
3answers
410 views

Which languages allow to mix its source code with C++ source code?

I have read that there are languages other than C++ that can also compile standard C++ source code too (Objective C++ can do this). Which other languages for Windows and Mac OS are there, that support ...
7
votes
1answer
82 views

Visitor Pattern, replacing objects

I have a program that translates a DSL to C++, which uses a Visitor pattern on the intermediate representation. I quite often need to replace the currently processed node with one of a different type ...
1
vote
0answers
82 views

How to structure enum data to achieve the desired effect

I'm making a framework for building simple html websites for an embedded system and I want to make it bulletproof in a way that a user can't make mistakes in building the html document. As I've ...
0
votes
2answers
135 views

C++ class vs function header file

I'm using C++ for implementing a project that requires to import a file once. All the data in this file needs to brought in memory as key value pairs, but only when the file is imported. Since this ...
5
votes
1answer
110 views

Algorithm to find span intersections in a sorted set

I have a set of items strictly ordered on time. Each item can either be single (no Next, no Previous) or part of a span (with either 1 or 2 further endpoints). For example in the picture A is part ...
3
votes
4answers
230 views

Is Template Pattern a good way to implement DRY?

Here is my problem: I have and class structure like this: class Base { private: SomeType something; bool isSomeValue; public: virtual void myMethod() = 0; ...
3
votes
1answer
136 views

Unique pointer initialisation

What is the correct initialisation of a smart pointer? std::unique_ptr<Class> ptr(std::make_unique<Class>()); or std::unique_ptr<Class> ptr = std::make_unique<Class>(); ...
3
votes
1answer
91 views

How do you manage your OpenCL source?

I am having a hard time deciding how I should manage my OpenCL source code so that my program can compile it at runtime. There seem to be two many strategies. You can create them in you C source as ...
28
votes
1answer
2k views

How does the C++ standards committee test their design ideas?

Does the C++ committee test their new design specifications with some sort of prototype compiler before releasing a new standard? Or do they release a standard which is, in effect, only theoretical ...
3
votes
1answer
515 views

In my situation, how could I learn to program without a mentor? [closed]

So my problem may be relatively rare, at least the majority of the "how to learn to code" questions I've come across deal with a lack of fundamental understanding of computers or languages. I'm fluent ...
0
votes
1answer
395 views

Recommendations to organize code changes in GIT

I'm looking for an advice reflecting my point of view. First, I will explain my point of view. My point of view I'm working in a big company as a C++ developer, we are using GIT. I'm going to make a ...
1
vote
1answer
94 views

Analyzing a C++ library with a diagram [closed]

When I want to read an entire library in C++ I start with class A. Then I realize class A is using function B. Function B is using class C and C2 and class C uses class D. I am aware that this ...
2
votes
0answers
114 views

Speed: Named Shared Memory vs Memory Mapped File vs Normal Memory

Let's say I have a server, where clients who connect are constantly updating their inventory. I could simply save the changes in to the database after an item has been updated, or I could update the ...
0
votes
1answer
161 views

Kernel facilities needed for C++

I'm working on a kernel for a proprietary embeded system. I've had no issues but I'd like to expand its capabilities directly. I made it run C. I did so pretty much by giving my kernel a stack. My ...
5
votes
4answers
320 views

Why is there a need for reference parameters in C++?

We've been learning about reference parameters in my Intro to Programming class. I understand perfectly that reference parameters give you access to the place where an argument is held in memory, ...
2
votes
2answers
157 views

C++ object references vs. lookup

Let's assume there are 2 classes: Country and City. Both of them have names, so a map would suit as conainer map<std::string, Country> countries; In the country class there is a similar map ...
2
votes
1answer
94 views

Best way to use a C++ style api from a C style file compiled in C++

I am working a in a Telecom company. We have some code generation tools that generate C style files based on a MIB definition. We compile them with C++ though. It boils down to the fact that these ...
1
vote
1answer
128 views

Async I/O operations - proper way to avoid deleting object

Using async I/O operations from boost::asio I often need shared pointers (and enable_shared_from_this and shared_from_this in callbacks) to avoid deleting objects too early. I think that it could be ...
1
vote
1answer
158 views

In C, are large 'pointer chains' bad for performance or code cleanliness?

The following for example: i = readString(&packet->data.play_server.updatesign.line1, pbuf, ps); It has a large amount of nested structs/unions. Is this generally frowned upon in code ...
0
votes
2answers
108 views

The way to implement a configurable (at run-time) default style

I am coding a visualizer of graph algorithms. Each vertex of the graph has a style (color, size etc.). As long as the algorithm has done nothing to a vertex, that vertex has a default style. The ...
4
votes
1answer
204 views

How to Structure Simple C++ projects for TDD

I am introducing Google Test into our development environment at work, and would like to encourage a TDD mindset, making this as accessible as possible for new developers to start using. I am looking ...
4
votes
2answers
101 views

Accessing members of a set by one of their properties

I often find myself in the situation where an object contains a set of objects, and I want to access one of these objects based on one of its properties. How I currently do this in C++ is to put ...
1
vote
2answers
121 views

C++ Parametric Polymorphism

In the wikipedia article on Parametric Polymorphism, is the following commentary on C++. Can anyone explain what it's referring to when talking about "ad hoc aspects"? (I think it needs a ...
4
votes
2answers
307 views

Designing an in-memory table in C++

I'm evaluating my options to structure an in-memory database and I have a few ideas of how to implement it. I would like to know your opinion of what the best design choice is. I have a column class ...
7
votes
2answers
256 views

Object reading from file, violation of SRP?

I am writing a physics simulation program in C++. I am a novice in OOP and C++. In my program, several objects need to be initialized based on data from an input file. For example, an imaginary ...
2
votes
0answers
44 views

How to architect rule matching with multiple conditionals and outcomes

I'm working on allowing my users to create their own ruleset for data that's coming in. All of the data below is sample mock data and not in relation to our product. Example of a rule (there can be ...
-4
votes
2answers
126 views

Repeating a Particular Iteration of For-Loop [closed]

I want to repeat a particular iteration of a for loop twice. The way I am doing it is that I am decrementing the index in that particular iteration. for(int i = 0; i < 100; i++) { ...
3
votes
1answer
318 views

Bad c++ code design? [closed]

This is bothering me a long time. I feel like I am doing mistakes on the code design relative to the performance. I never had any teacher to indicate my mistakes so its hard to me to make it right in ...
5
votes
4answers
520 views

Is it a good idea to document every assumption in code, even if it goes against the standard of the language?

For instance, would this c++ function be a good idea? void doSomething(not_nullptr<MyType> arg) { // stuff } With not_tullptr being a template wrapper for pointers, that will throw an ...
0
votes
1answer
72 views

Blocking queue for token based synchronization

I'm currently looking for a good solution for the following use-case in C++ (preferably C++11 or C++14): The program is running a server with a TCP connection. Other clients can connect at any time ...