Questions tagged [c++]
Questions about C++, a statically typed, free-form, multi-paradigm, compiled, general-purpose programming language.
2,583
questions
0
votes
4answers
291 views
Open closed principle: code duplication and encapsulation
In another question on this site, asking to clarify the open closed principle, @Kate Gregory answered this.
I'm interested in this part specifically:
Imagine you wrote an Invoice class that works ...
1
vote
1answer
132 views
In C++, how would one unit test a method that must throw an exception when a private array no longer has "space"?
I am implementing an ECS system with a data-oriented design, and with a TDD methodology using Catch 2. I have the following class declaration snippet for an EntityManager:
using Entity = std::...
0
votes
0answers
45 views
Logically equivalent conditionals, same test, but different condition coverage (google test)
Title pretty much says it. I ran into trouble getting condition coverage of a logical statement and found that the order in which the statement is written (rather than order of operations) results in ...
0
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0answers
88 views
Ensure that library has been initialized
I am using a 3rd party library that must be initialized with Lib::init() before any of its other functions may be called and that must be uninitialized with Lib::destroy() before the application ends. ...
2
votes
2answers
130 views
Organization of C++ source code for reusable components
I'm implementing a custom templated container as part of a learning project in C++. The container makes use of different components like serialization, memory management, iterators. I am wondering ...
-1
votes
1answer
44 views
Non regression test for small set of data data driven from database, how to handle future data
While writing this question I found out that I'm faced with 2 problems: a testing one and a production one but I hope that resolving the situation can solve both issues.
Now the question:
I have a ...
4
votes
5answers
784 views
How to deal with a lot of conditions in If statement in an elegant manner
Is there a more syntactically beautiful/simply better way to write the following (without major abstraction)?:
if (usart_error.CRCError == true || usart_error.DMATransferError == true ||
...
4
votes
4answers
769 views
Do we really need interface classes for the dependency inversion principle?
As a practical example, imagine a Gripper class which represents a robotic gripper in a simulation.
Gripper has a TryGrip method, which checks if there's a GrippableItem in the correct position (...
-2
votes
1answer
474 views
In C++ and GCC on Linux, is it possible to allocate memory to your swap space instead of your RAM?
I have a large hash, around 6 gigabytes that I load into memory. On my current laptop that I develop from, it really does a number on my system, causing massive amounts of lag while I try to go about ...
2
votes
5answers
278 views
Splitting class responsibilities without exposing private data
I'm struggling to find good ways to split up classes without exposing private data. Most articles I read about SRP seem to ignore how the new classes that take on the separated responsibilities access ...
1
vote
2answers
266 views
How to declare and share a lot of variables to provide best performance
My question is not about dilemma between clean code vs performance, but I want to understand exact issue with declaring variables and sharing them between functions.
I read in many threads, that from ...
1
vote
0answers
57 views
External standalone cpp code in my project
I've inherited a project that has a codebase in src/, but it also has precompiled binaries of dependency software in bin/. I would like to move away from having precompiled software as part of our ...
5
votes
2answers
310 views
Where can I put project dependencies
I've just finished my studies in Computer Science and now I'm working.
The problem is I'm the only computer scientist in my company and I'm probably taking a lot of bad habits. I would like to correct ...
0
votes
2answers
502 views
Logically, is there a reason why ++i++ can not be a valid expression?
I had to increment my integer twice in a loop, so I thought I would try and be clever:
for (int i = 0; !sl.isEmpty(); ++i++) { ... }
++i++ however is not an assignable expression, at least in GCC.
...
3
votes
2answers
254 views
Am I using namespaces wrong?
I'm obsessed with organization - it's probably the real reason why I enjoy coding. So I namespace everything. But I'm just curious if I'm doing it wrong by being redundant.
Consider this, which I ...
6
votes
1answer
216 views
Is it practical to pass function pointers to a separate class to avoid additional includes?
In my program I've included the header for an external library (GLFW) in my Main class. Everything I need to use that library for can be handled in my main class, with the exception of two sneaky ...
6
votes
4answers
310 views
How to explicitly inform users of the class that calling a method will invalidate the object it was called upon?
Consider this snippet:
class Foo
{
int m_fileDescriptor;
public:
Bar transformIntoBar()
{
Bar bar(m_fileDescriptor);
m_fileDescriptor = -1;
return bar;
}
};
...
1
vote
2answers
116 views
const function parameters and default behavior
Say I have a C++ function
/**
* @param path If empty, the system default is used
*/
void foo(const std::string& path);
And in my implementation I have a default handling for empty paths
void ...
7
votes
8answers
735 views
Relevance of optimization techniques
I've heard of some techniques to optimize code and make it faster:
On one side are clearly relevant optimization: use of better algorithms, benchmarking, etc.
On the other side are techniques with a ...
0
votes
0answers
72 views
Different approaches to plugin system
Having an application that defines a plugin API, I was wondering how (if possible at all) to achieve both stability and performance (see below for what that means) at the same time.
A plugin in my ...
1
vote
2answers
1k views
Simple Snake Game in C++
I posted this question originally in Code Review, but then thought that I could possibly get more feedback about the design here.
I just finished writing a simple Snake clone in C++ with the goal of ...
0
votes
4answers
130 views
Design pattern for embedding constructor arguments into classes/structs
I am still quite new on here so I hope I am posting in right forum.
I am currently writing a small library where I realized I could use some kind of design pattern which lets one pass constructor ...
25
votes
4answers
5k views
Why is the norm of a complex number in the C++ complex library actually the square of the norm?
In the C++ complex library, the method norm() of a complex number actually returns the square of what I have learned is usually called the "Norm".
Reference: std::norm
For example, std::norm() of (3,...
1
vote
1answer
94 views
How to simplify work with class inheritance when a lot of arguments needed to be passed to c-tor?
Let's say I have class that used inside another class and uses inside some nested fields of it. To simplify the example I'll use trivial types. In reality it's something like DataType dataType, Status ...
2
votes
0answers
127 views
c++ exceptions, should the caller add the context or provide it to the callee?
Here is a piece of code. Basically, I load some source files, all of them are compiled separately, and then I link all of them.
LinkedObject loadObject(std::vector<std::string>& fileNames)
{...
-1
votes
2answers
125 views
Developing a C++ program on linux using two threads, always keeping one thread running
The title describes an idea of a solution to a more general problem. Here is the general problem:
I am developing a program which looks roughly as follows:
[read a lot of data, store in data ...
-2
votes
1answer
102 views
Design a generic hardware interface
I am trying design a generic hardware facade interface for different camera types.
below is my incomplete generic interface for camera devices
template <class Data,class Configuration>
class ...
-1
votes
2answers
181 views
where to put Read/Write threads in c++ classes
I am programming a UART interface (in LINUX) and I want to use a class for that.
The way I have it right now is I have a method for write and one for read.
The reading is started in a new thread to ...
5
votes
2answers
2k views
Is it good approach to await async tasks in object destructor?
I'm currently working on class with some async tasks under the hood. In fact I need to delegate few tasks to asynchronous execution and be sure that all of them are finished before class was destroyed,...
1
vote
0answers
54 views
Include a database .h file in the factory or in the class in C++
I have a factory, GuiTable.cpp where I create multiple GUI-related classes. I also have a database class, CommonStrDatabase.h which serves as a database file for different strings used in the GUI.
...
0
votes
0answers
92 views
Best design for referring to compile-time set of values at runtime
I am designing an internal API that deals with images.
As part of this, I hit this use case where:
I specify an image format as a single value.
An image format implies a collection of settings (...
4
votes
3answers
556 views
What's the purpose of multiplying by 1024x1024?
I'm working with an old C module that was originally ran on Power PC architecture and compiled with gnu 3.0.6
I'm porting it to run in a VS2012 project on Intel hardware.
The module creates a 3D ...
2
votes
1answer
131 views
Optimal design for improved performance of a simulation code
I'm writing a code for the Discrete Element Method where I have balls (spheres) and walls (planes) interacting with each other.
Those simulations are run for billions of time steps, so performance ...
1
vote
1answer
430 views
Whats a proper way to design a GUI event system?
I'm trying to write a GUI library for a project (also for learning purposes) from scratch (in C++), and it's working pretty well, but since this is my first attempt i feel that the design of the event ...
4
votes
3answers
417 views
How to adhere to the Open Closed principle in a procedural language like C
In Robert Martin's seminal 1996 article "The Open-Closed Principle" he presents an example in C which does not follow the principle (the DrawAllShapes() method is not closed for modification):
enum ...
2
votes
2answers
106 views
Processing user commands and parameters
I'm writing a GUI application which needs the facility for users to interact with the system and execute tasks via a sort of command line interface.
The user will type commands in a text box, with ...
1
vote
1answer
489 views
What are the possibilities to embed GIT into application in order to manage version control of the projects that were created by that application?
I am developing an C++ application, which creates tree like structures (collections) of strings. I want to add the ability to save the information of these tree structures remotely/locally (can be ...
25
votes
7answers
6k views
Can abstractions and good code practice in embedded C++ eliminate the need for the debugger?
I am a C developer for an embedded system. YouTube has recently started recommending "C++ for embedded systems" talks. Having watched some of them, they pique my interest, but none of them answer the ...
12
votes
6answers
2k views
why aren't the platform specific integer types in C and C++ (short, int, long) deprecated?
TL;DR: Why isn't everybody screaming, "Don't use short, int, and long unless you really need to, and you very likely don't need to!"
I understand that, in theory, by using the types short, int, and ...
4
votes
1answer
104 views
Coupling and shared entity classes
I am currently working on a problem that has a central controller that is handling inputs and outputs between various modules and maintaining a number of entity classes as these change. When working ...
-2
votes
1answer
885 views
How to make code runnable on open source code editors like Ace Editor?
For my computer science uni project I'm required to build a web application with an integrated code editor. I believe I can just integrate open source editors like Ace Editor.
However, I feel ...
3
votes
1answer
116 views
Keep track of intializations done in a function
There is an initialization function in my app that does multiple inits. What is a good way to keep a track of inits done so that if init n fails all inits done before it must be cleaned up/de-init ...
1
vote
1answer
265 views
Public class members in PIMPL
I'm attempting to use the PIMPL idiom. This is my public header file in include/foo.h:
class FooPrivate;
class Foo {
public:
Foo();
~Foo();
private:
FooPrivate* p_impl;
};
...
1
vote
2answers
158 views
Is there a natural architecture design where I should use mutable member variable(c++)?
I have come across mutable variables kind often, yet it seems to me it's always been use to solve
a problem of design(typically coping with legacy code) rather than to answer a natural, intrinsic ...
0
votes
0answers
104 views
C++ client-server design
The context
I need to design a Client-Server(-Client) network in C++ that would allow an android application to communicate to a Raspberry Pi and back
I am running everything on linux environment(s) ...
5
votes
2answers
259 views
How to best unify different data formats?
I have a hardware device connected to the computer and on the hardware device there is 512 bytes of memory for storing parameters. I want to read this data and decode the parameters stored in the ...
2
votes
4answers
2k views
How to use Macros in Programming to make code faster, efficient and compact
Recently I was going through some of the source-codes of the best competitive programmers in the world. I found out that those people use a template while writing programs, preferably in C++.
I have ...
5
votes
6answers
4k views
Is there a way to speed up a big switch statement?
As a practice I'm working on a CPU simulator (runs at about 1.78MHz) and I'm using a switch statement to execute correct opcodes based on the value in the IR (instruction register) variable. This ...
-1
votes
2answers
65 views
OOP classes hierachies for aiding static checking justified?
upfront I develop software for big data applications of which use is beyond my control (it ends up with a user), but I am not a trained software developer. So I apologize for any wrong terminology.
...
3
votes
1answer
225 views
(C++) Ideal design pattern for associating requests/responses on socket?
I'm working on my first big C++ project and while I understand the language I'm trying to learn elegant design patterns using it. I have some low-level networking over a UDP sockets API where each ...
