General C++ Programming

Welcome to the general programming forum in C++.com! In this forum, users can to talk about any topic related to programming in the C++ language that does not ...

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by CactusBack

Euler Angle Compression

I realize this is probably more of a math question than C++ question but I figured I might as well try asking here too since it is in the context of a C++ tool,...

[2 replies] Last: It looks to me like the rotations are simply discarding a coordinate f... (by Duthomhas)

by Laurent7601

Cylic inclusion and forward declaration and template issue.

Hi, I've two classes (Server and Network) which have a template function defined in the .h file because we must define template function to header files. The p...

[3 replies] Last: For others interested, here was my original example now split into mul... (by Ganado)

by Laurent7601

How to init this static var

Hi! I've a template class Application which have a static var. (a pointer to the application instance) I declare it like this : static Application<A, T>* app...

[2 replies] Last: Templates need to be defined in the header file (unless you add explic... (by Peter87)

by Xaxazak

discussion on std::ranges::iterator_t<T> being distinct from T::iterator (and same for begin)

I recently spent an hour or so on a bug that came down to std::ranges::const_iterator_t<T> sometimes being different from T::const_iterator. For example: === s...

[4 replies] Last: [quote=Xaxazak]I recently spent an hour or so on a bug that came down ... (by TheIdeasMan)

by Ganado

Safer way to maintain struct initializations

I ran into this problem a bit ago, and was wondering what future-proofing refactor people would suggest. Let's say I have a struct that just contains some simp...

[5 replies] Last: Maybe you want to take a look at the "pimpl" (pointer to implementati... (by kigar64551)

by Heyyo53

PNG File Reader (1,2)

I have been on a quest to write some kind of PNG file reader, mostly just for myself, and I was wondering if there is any good resources on how to do binary fil...

[38 replies] Last: Hmm... learning something new. According to cppreference.com it is on... (by Duthomhas)

by kitfox

How to create white noise random hashing function?

I'm trying to figure out how to build a random hashing function that emphasizes speed and repeatability. Basically, for input it will have an unsigned int seed...

[1 reply] : I think you can use any proper hash function to produce a (pseudo) "... (by kigar64551)

by bistelA0005

Use C++ 20 with Embarcadero

I have been using C++ builder for some C projects. It works really well. However, I have been trying to run some code from a tutorial I want to follow and I get...

[4 replies] Last: The last recourse is the "other compiler options" where you can just l... (by salem c)

by BernardIE5317

Call of Templated Function w/ Explicit Template Argument Fails to Compile

greetings kind regards may i please enquire why compiler reports error for code below as indicated . thank you kindly template<typename T, typename U> voi...

[1 reply] : The meaning of the name _T.aaa depends on the template parameter T ... (by mbozzi)

by PhysicsIsFun

scientific computing - optimize speed

Greetings, this is a longer thread, so thank you in advance for anyone who takes the time. It might be that no one can help me without sharing the whole github...

[16 replies] Last: Just leaving this here. https://en.wikipedia.org/wiki/Barnes%E2%80%93... (by salem c)

by stonedviper

why can't I use cout with without iostream

Basically what the tittle says I wanted to output something so I only included the ostream library but when I tried to output something with cout i saw ...

[5 replies] Last: And then there is <iosfwd> (by keskiverto)

by PhysicsIsFun

Pybind11 slows my C++ code substantially

Greetings everyone, continuing with my particle simulation, I am trying to turn it into a python package (I work in maths, and most people would never be able ...

[4 replies] Last: of course it can. you may need to hand wave at byte ordering if you g... (by jonnin)

by leo2008

anagram using vector

I am trying to solve this problem. Are there any other better approaches here? Implement a function which takes a list of words as an argument and finds all a...

[2 replies] Last: If you go big (a large dictionary of words) you may want to move out t... (by jonnin)

by JUANDENT

Making a shared_ptr out of a stack object corrupts the heap!!

Hi, The following code is incorrect: Customer customer = { 0, "John Doe", "johndoe@example.com" }; auto cc = std::make_shared<Customer>(customer);...

[2 replies] Last: Note: std::make_shared<T>() creates a new heap-allocated instance of... (by kigar64551)

by JamieAl

Testing restart functionality in C/C++

Hello! I am trying to implement "restart" functionality in my code, where if for some reason the code stops (i.e. iterations drop) I can pick up from where I s...

[1 reply] : you will get more help if you put it in a repo where we can see the co... (by jonnin)

by JUANDENT

Need a data structure where I can map a string to a type

Hi, Need a certain compile time map m like this: using Type = typename m["Customer"]::type; // Type would be Customer How can i do this? Regar...

[10 replies] Last: It's not necessary to use an enum. It was just a suggestion. (by Peter87)

by Coubarrie

Save to file with vector (dynamically)

I have created a programme that does calculations and generates results from those calculations. The imformation generated is stored in variables for later d...

[11 replies] Last: i outside the loop is not a c++ error. It is a questionable programmi... (by jonnin)

by JUANDENT

what does T = 0 mean in a template parameter?

What does T = 0 mean in the following code: template<typename T, T = 0> T moduloOf(T a, T b) { return a % b; }

[4 replies] Last: Indeed: "initialized with value 0" limit what type the T can be? (by JUANDENT)

by LsDefect

When does early binding happen?

Thing 1: Static binding takes place during compilation - function calls are replaced with an instruction saying "go here for the appropriate function definit...

[1 reply] : I guess this is what's called "devirtualization" which GCC has optimiz... (by Peter87)

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