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

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4
votes
5answers
198 views

How to store math expression in c++ list

I am parsing a infix math expression to a postfix form. I want to store it in a list like [4.5, 3, 0.25, +, -] so that I can process it once it's parsed. I could store it in a string again, but I ...
0
votes
0answers
49 views

Should frequent Fonts, Colors, Pens etc be “Cached”

I am creating a game, currently everything redraws every 50ms, and that involves quite a few Gdi Objects. Here: Gdiplus::Pen outlineScrollPen ( Color (200, 0, 0, 0), 4 ); ...
1
vote
2answers
104 views

Ideal OOP Design

After learning OOP design then I got to know my programming way was not correct. One should convert physical entities or logically separable components into classes which are reusable and have their ...
119
votes
15answers
29k views

Why do people use C if it is so dangerous?

I am considering learning C. But why do people use C (or C++) if it can be used 'dangerously'? By dangerous, I mean with pointers and other similar stuff. Like the Stack Overflow question Why is ...
5
votes
2answers
211 views

Why does ifstream.eof() not return TRUE after reading the last line of a file?

When a beginner starts off reading ifstreams, his/her instinct is to read the file using a loop that usually looks like this: while (!ifstream.eof() { ... } However, C++ programmers note that what ...
4
votes
0answers
92 views

Does it make sense to apply the principles in Redux to OO languages?

Redux is essentially functional programming, and it makes a lot of sense. As I move back to a non-javascript OOP language in a different project I would like to apply the same principles such as ...
61
votes
18answers
3k views

Why should I care about micro performance and efficency?

Many questions and answers on the C/C++ pages, specifically or indirectly discuss micro performance issues (such is the overhead of an indirect vs direct vs inline function), or using an O(N2) vs O(...
8
votes
1answer
6k views

raw, weak_ptr, unique_ptr, shared_ptr etc… how to choose them wisely

There is a lot of pointers in C++ but to be honest in 5 years or so in c++ programmation (specifically with the Qt Framework) I only use the old raw pointer : SomeKindOfObject *someKindOfObject = ...
1
vote
2answers
61 views

Installing multiple versions of software with git

I'm really struggling to understand git, so here's a tighter rephrasing of a previous question I had asked. I'm going to explain a hypothetical scenario, detailing what I think happens when you ...
0
votes
2answers
115 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 ...
0
votes
1answer
162 views

How assembler coverts to machine code 1 and 0 [duplicate]

I know that assembler is the one which converts to machine code. So here in 8085 instruction set LDA has opcode "3A". My question is how assembler convert mnemonics to opcode and finally to machine ...
2
votes
3answers
208 views

Why is the next element of an int array stored 4 bytes after the previous one?

I have this small code: int* array_int = new int[10]; array_int[0] = 1; array_int[1] = 2; array_int[2] = 3; array_int[3] = 4; array_int[4] = 5; array_int[5] = 6; array_int[...
1
vote
2answers
154 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
3answers
193 views

Define C++ class in one or more files

When creating a C++ class what is best practice> Put the entire class definition and member functions in a header file Put the class definition and function declarations in the header file and put ...
1
vote
2answers
111 views

Dynamic gesture recognition with fingertip points

I have built a fairly robust program in c++ which tracks several points on a hand. It accurately quantifies the size of the palm, the center of the palm, and the fingertip locations among other hand ...
-2
votes
1answer
172 views

Calling an entire script (in C) from another script (in C++)?

I am a very inexperienced programmer, so apologies if this is a stupid question to be asking. And similarly, if anyone answering could assume that I know basically nothing at all and treat me like an ...
2
votes
0answers
75 views

Using and designing asynchronous APIs with naturally synchronous parts

I've been programming for a long time, but very rarely with anything asynchronous (and not often with anything to do with multithreading, either). Mostly for the fun of it, I'm writing a program to ...
6
votes
10answers
1k views

Languages to complement C++ [closed]

I primarily work in C++. My question is, for a C++ developer, what languages are beneficial to learn, from a job-profile point of view. For example, I see a lot of work combining C++ and Php these ...
41
votes
3answers
69k views

What is the role of C++ today?

Currently I'm an IT student and I'm wondering what is still important in C++ today, what for is it used? I completed basic C++ course in my university but I can't imagine where can I use my knowledge ...
0
votes
1answer
106 views

Should smaller data types be used in intermediate code?

I often use smaller data types in structs/classes when it is needed in memory savings. I also use them in network/disk IO. My question is if intermediate code that use those objects with smaller data ...
1
vote
3answers
191 views

On a modern compiler, how do I intentionally code for 2s complement with wraparound?

I want to compare sequence numbers (given to this code from elsewhere) that may wrap around. Simply comparing two such values will not handle the case like 0x00000002 being greater than 0xfffffffd, ...
0
votes
0answers
22 views

Creating and passing new object in parameter

I have a wrapper class which contains a smart pointer (unique) which can point to objects which are subclasses of State. Each subclass of State receives a reference to the wrapper class so that the ...
1
vote
1answer
108 views

when writing platform specific code, is using separate .cpp always preferred instead of using #ifdef?

I have some platform specific code, such as a string needs different values at different platforms like it: test.cpp #if(PLATFORM==ANDROID) string url="android"; #elif(PLATFORM==IOS) string ...
2
votes
5answers
340 views

Why do I need to declare virtual functions as such?

Example: We have a base class Base and three subclasses which all implement their own version of doSomething(). In an intermediate function f(Base b), we want to call the relevant version of ...
-1
votes
0answers
63 views

Integrating IDE with docker C++ toolchain

I have created a docker in order to compile C++ applications using a third party toolchain. My ideal work environment would be to leave the sources on my local directoy and to use the docker only for ...
0
votes
1answer
87 views

What data structure to use to save the address of edges in depth first search?

I am currently trying to write my own Depth First Search. I have created a class called node. class node{ private: bool is_visited; <data structure to collect edges> ...
13
votes
7answers
1k views

Does C# experience translate well to C++? [closed]

My programming classes in school were C++, but I ended up working a job doing C# for the last few years. If there was a position that required say 1 or 2 years experience in C++, would my experience ...
0
votes
1answer
59 views

How to traverse “linked list” like structure with parallel nodes

I am working on a signal processing project that allows for parallel processing on data streams as well as inputs and outputs to and from multiple endpoints. The signal chain is broken down into "...
2
votes
2answers
96 views

C++ vs Java: Pointing to Objects

In Java: private State current_state; As "State" is a superclass, I can then assign subclass objects to current_state, effectively making current_state point to a different object: current_state = ...
4
votes
2answers
83 views

How to facilitate thread-safe access to large set of shared variables?

I have 2 sets--inputs and outputs--of 70 32-bit integer variables and 70 bools (140 vars altogether). These need to be accessed and modified from 3 threads. What is an appropriate design pattern to ...
9
votes
1answer
156 views

Idiomatic wrapping of C++ template type API in C

I'm working on wrapping a C++ API which provides access to a data store (Hazelcast) in C functions, so that the data store can also be accessed from C-only code. The Hazelcast C++ API for the Map ...
1
vote
1answer
95 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 ...
2
votes
1answer
36 views

Configuration related defines in public header?

Suppose you're building some library, C or C++ doesn't really matter for this question, IMO. The features (or implementation thereof) depend on capabilities of the target system. A simple, probably ...
32
votes
10answers
3k views

The “blub paradox” and c++

I was reading the article here: http://www.paulgraham.com/avg.html and the part about the "blub paradox" was particularly interesting. As someone who mainly codes in c++ but has exposure to other ...
2
votes
0answers
71 views

How to combine template and inheritance

I have multiple factories, each is responsible for creating instances of an inheritance tree. For example (syntax or semantics maybe incorrect), struct InterfaceA {}; struct ImplA1 : InterfaceA {}; ...
4
votes
2answers
147 views

Passing readonly structs in C++

In this particular problem I am having, I am not sure of the proper way to deal with readonly structs, passed to class constructors as a parameter when I want to store the data in the struct, in the ...
49
votes
10answers
11k views

Why would the 'final' keyword ever be useful?

It seems Java has had the power to declare classes not-derivable for ages, and now C++ has it too. However, in the light of the Open/Close principle in SOLID, why would that be useful? To me, the ...
0
votes
0answers
28 views

Help me understand this flow for recursive function [duplicate]

This recursive function blows my mind a bit because it executes the recursive calls until it hits 1. It returns n, but afterwards it does the multiplication below it four times and returns the final ...
6
votes
5answers
382 views

Is it wise to rely on optimizations?

Should I write my code to be clear what I am doing and rely on the optimizer to clean up my code efficiency, or should I be obsessive about getting every last ounce of power out of my code? And how ...
2
votes
2answers
198 views

In C++, why shouldn't all function parameters be references?

I am currently learning C++ from the C++ Primer 5th edition. The book's chapter on functions states that only large objects (large being relative as standard library strings count, but "primitive ...
5
votes
6answers
4k views

Template Functions and Function templates in C++

I came across a question which asked the difference between Function Templates and Template Functions in C++ and also Template Classes and Class Templates. I was under the impression that Function ...
2
votes
1answer
127 views

Fine tuning details in C++ function for different customers

The company I work for follows a business model where a core product exists (originally written in C, now in C++) with some default implementation but details are tailor-made for each customer (there ...
1
vote
1answer
106 views

Static memory idiom

I am on a micro controller (which means I can only have static memory allocation) and I am trying to work with inheritance..... Suppose I have a abstract class Image and an abstract class Font. An ...
17
votes
1answer
415 views

How does Rust diverge from the concurrency facilities of C++?

I am trying to decide whether Rust fundamentally, sufficiently improves upon the concurrency facilities of C++ that I should spend the time to learn Rust. In light of Stackexchange's format, I should ...
2
votes
1answer
293 views

Feeding std::streambuf for Non-Blocking std::istream Read

I want to write small library to guide a child process for a specific needs (not trying to reinvent bicycle here). My needs includes reading from child stdout and stderr. I want to implement this as ...
-1
votes
1answer
150 views

What is the faster way to save and browse objects using vectors +/or maps? (c++)

I'm doing a object Garbage class using c++: #include "Object.h" class ObjectGarbage { public: ObjectGarbage(); ~ObjectGarbage(); void Call_All_Objects() { //(...