Does anyone know what happened to learncpp.com? There haven't been any new posts there in the last two years. Will the site be updated in the future?

Here is the "play" function currently:

void play(char **frames, int totFrames){
    int i, j;
    char music[200];
    strcpy(music, DIRECTORY);
    strcat(music, FILEMUSIC);
    PlaySoundA(music, NULL, SND_FILENAME | SND_ASYNC);


    for(i = START; i < totFrames; i++){
        resetCursor();
        #if DEBUG
        char framesCount[100];
        sprintf(framesCount, "(frame: %d/%d) \n", i+1, totFrames);
        int x=WIDTH-strlen(PROJECTNAME)-strlen(framesCount);
        for(j = 0; j <= x; j++)
            printf(" ");
        printf("%s", framesCount);
        printf("%s", frames[i]);
        progressBar(i, totFrames, 0, 0);
        Sleep(WAIT);
        #else
        printf("%s\n", frames[i]);
        Sleep(WAIT);
        #endif
    }
}

It starts playing the music and then loads the video frames from a directory which contains every frame of the Bad Apple video one after another. The problem is that the music and the video is initially in sync but slowly drifts out of sync until it's completely out. I think the <chrono> library is what you would use to fix this type of issue but I'm not sure how to implement something that syncs the audio and video while also keeping the video smooth and not slowed down. I've also tried making an FPS limiter but I don't know if this is the right approach. Also I know this looks like C code and it it originally but I converted this program to C++ in order to use libraries like <chrono> and because I generally prefer C++

If you want to see other snippets of code from the program, just ask.

Currently working on profiling a Huffman data compressor and I'm working on optimizing a bit writing bottleneck. For context, the compressor goes through a text file and writes each character's bit representation into a file.

...
ifstream file(inputPath, ios::binary);

    char buffer[4096];
    while (file.read(buffer, sizeof(buffer)) || file.gcount() > 0) {
        streamsize count = file.gcount();
        for (streamsize i = 0; i < count; i++) {
            char c = buffer[i];
            const HuffmanTree::Encoding &encoded = encodings[static_cast<unsigned char>(c)];
            writer.writeBits(encoded.encoding, encoded.size);
        }
    }
...

writeBits takes the encoding and the size of the encoding in bits and writes it into a 4096 size buffer. When the buffer is full, we then use the write function to actually write it into the desired file.

...
void BitWriter::writeBits(uint64_t bytes, uint64_t size) {
    assert(size <= 64);
    assert(size == 64 || (bytes >> size) == 0);
     while (size > 0)
    {
        const uint64_t available{
            8ULL - current_size
        };

        const uint64_t bitsToTake{
            min(size, available)
        };

        // Select the next highest meaningful bits.
        const uint64_t shift{
            size - bitsToTake
        };

        const uint64_t mask{
            (uint64_t{1} << bitsToTake) - 1
        };

        const uint64_t chunk{
            (bytes >> shift) & mask
        };

        current_byte = static_cast<uint8_t>(
            (static_cast<uint16_t>(current_byte) << bitsToTake) |
            chunk);

        current_size = static_cast<uint8_t>(
            current_size + bitsToTake);

        size -= bitsToTake;

        if (current_size == 8)
        {
            bufferByte(current_byte);
        }
    }
}
...

Linux perf is indicating this is hot but I'm unsure of what would be a better approach. Any ideas?

I have just set up my vs code for c++ learning on my new device. I was told i can't run modern c++ on older version of this. Is that true? If yes then how do i upgrade?

I mainly use VSCode for my c++ projects, even though I have Visual Studio installed.

My tools are MSYS2, and I have the UCRT64 gcc and UCRT64 ming-make32 as well as cmake.

I set everything up using CMakeLists and git for version control. However, for my compiler, I use g++ and not MSVC even though I have it installed. Is it worth it to swap to MSVC, or will g++ work?

EDIT: Thank you all so, so much for all the insight! I'm probably going to set up clang!

EDIT 2: Again, thank you so much! I have successfully set up clang with MSYS2, and that will be my main compiler now.

Hey everyone,

I am currently trying to implement a programming language in C++ after having come pretty far, but ultimately failing to do so in C.

For this, I am taking pretty big inspiration from craftinginterpreters, and am now trying to mimic its implementation of the visitor pattern (entire class at once), written in Java.

However, that implementation uses both templates and interfaces.

As far as I'm aware (the entire internet seems to say so at least), in C++, interfaces are represented by classes whose functions are all virtual.

However, If I try code like the following:

    template <typename R> class ExprVisitor {
    public:
        virtual ~ExprVisitor() = default;

        virtual R visitBinaryExpr(const Binary* expr) const = 0;
        /* other visitor functions...*/
    };

    struct Expr {
        virtual ~Expr() = default;
        template <typename R> virtual R accept(ExprVisitor<R> *visitor) = 0;
    };

(Of course, all of my nodes like Binary inherit from Expr. I use structs instead of classes because everything needs to be accessible from the outside for my purposes, so I don't need to re-type "public:" every time.)

Then I get an error on the line declaring the accept method saying

Template function 'R Expr::Expr::accept<R>(ExprVisitor<R> *visitor)' cannot be virtual

on the virtual keyword, as well as one saying

Pure member function 'Expr::Expr::accept<R>' is not virtual

on the = 0 part.

I've googled around a bit, but the only implementations I was able to find were only able to pass in the template type, not get it back out as a return value.

Is it even possible to achieve this? Am I using templates incorrectly? I saw something using variadic templates but was not able to get it working, either.

Any help would be extremely appreciated!

I was looking on cpprefernce the other day at std::construct_at and I wanted to test the code. But when I ran it it did not compile. I ran the snippet without consteval (and static_assert) and everything worked. Does anyone know what might be the issue? https://en.cppreference.com/cpp/memory/construct_at

Code:

#include <bit>
#include <memory>


class S
{
    int x_;
    float y_;
    double z_;
public:
    constexpr S(int x, float y, double z) : x_{x}, y_{y}, z_{z} {}
    [[nodiscard("no side-effects!")]]
    constexpr bool operator==(const S&) const noexcept = default;
};


consteval bool test()
{
    alignas(S) unsigned char storage[sizeof(S)]{};
    S uninitialized = std::bit_cast<S>(storage);
    std::destroy_at(&uninitialized);
    S* ptr = std::construct_at(std::addressof(uninitialized), 42, 2.71f, 3.14);
    const bool res{*ptr == S{42, 2.71f, 3.14}};
    std::destroy_at(ptr);
    return res;
}
static_assert(test());


int main() {

Compiler Error on x86-64 gcc 16.1 -std=c++23

<source>:25:19:

error: non-constant condition for static assertion
   25 | static_assert(test());
      |               
~~~~^~
<source>:25:19: in 'constexpr' expansion of 'test()'
<source>:24:1: error: destroying 'uninitialized' outside its lifetime
   24 | }
      | 
^
<source>:18:7: note: declared here
   18 |     S uninitialized = std::bit_cast<S>(storage);
      |       
^~~~~~~~~~~~~
Compiler returned: 1

I really want to get into programming and want to learn C++, but I really am confused on where to start, and what some things are that can really help me learn and understand everything. So what would be the best ways to learn, such as books or videos and if so which ones? Any advice would be amazing!!

Hi all, just like the title stated, I know AI is the thing and I have been using it to help me understand on various topic and design on coding. I still learned a lot from AI when I asked a question. But the more I use AI, the more I hate myself on the part where I feel dumb that I cant learn by myself. I've been using CPP to build a small project lately, nothing too fancy but just to refresh my memory from the past. Throughout the process, I tried to limited the use of AI and use documentations and forums like stackoverflow to check out my questions, but in the end of the day I either ended up cant understand the documentation, got overwhelmed by the answers, or just can't find what I needed. Eventually I have to return back to AI and ask the same question and let AI to break it down while also to get feedback on my ideas. I don't hate AI in general (but I hate my dumb self instead), using too much AI is going to kill my thinking skills, I want to try my best to avoid that scenario.

The thing is that I always got overwhelmed by advanced topics no matter in Java, Python, JavaScript, or CPP. Like I can understand the fundamental stuffs very easily, but gets bottlenecked as soon as I deal with advanced topics (anything beyond the basic oop stuffs and general algorithms).

Thank you so much for your time to read this big chunk of paragraph and I apologize in advance if my question sounds dumb.

Sorry about the title, I should have read the guide first. I am really new to C++. I am going through the practice guide on a youtube video. The test was to make a fahrenheit to celcius conversion. This is what I wrote and it is below. 
The teacher added     double celsius = (fahrenheit -32) / 1.8;
Then added the std::cout for it. Mine works fine. I am assuming his is better but I am missing it. c++ has made me question my mental capacity.

#include <iostream>

int main() {

std::cout << "Enter degrees in fahrenheit ";
int fahrenheit;
std::cin >> fahrenheit;
std::cout << " Degrees in celcius " << (fahrenheit - 32) / 1.8;





return 0;



system("<pause>0");

I'm building a general purpose small container, with a fixed known capacity.

It's basically a thin wrapper around a C array. But, in case I would need to store objects without default constructors, I thought I might make another version of the same container, that would allocate the necessary memory on the heap without building anything inside.

But I'm afraid I opened up a whole new can of worms. The first idea I had was to do the same, but replace my array with an std::vector of appropriate capacity. But I'm sure there are better ways, maybe use "operator new" but I'm not quite familiar with all the methods to properly align memory.

I guess the question is : do C++ people often do that kind of low level memory managing or is the better practice to build around common tools (such as std::vector) ?

Hi I have a question about VSC. I'm used to compiling and running programs by clicking an button in UI like in arduino IDE or panasonic or siemens PLC enviroments. When i run a C++ program via F5 button everything works just fine (i mean the value near cout appers in the terminal), but when i run it through UI button i uperright corner, selecting any of the options it does not appear

Is this c++ course still relevant even though it is 8 years old? https://youtu.be/vLnPwxZdW4Y?si=m63NVhTp2kYVkVaC

Hey everyone, I found that LearnCpp is one of the best resources for learning C++, and after looking through the website, I really like how the content is organized from the basics all the way to advanced topics.

The reason I’m making this post is that when we learn something on our own, there are so many different ways to approach it. Sometimes we spend a lot of time learning the hard way and later realize there was a much better approach. Other times, we might not make much progress simply because our learning strategy isn’t very effective.

So I’d like to hear from people who have learned C++, especially those who used LearnCpp.

How did you start and progress from beginner to more advanced C++? If you used LearnCpp, how did you go through it? Did you complete it chapter by chapter, or combine it with other resources?

At what point would you recommend starting projects? Are there certain chapters or topics someone should understand before trying to build real projects?

I’d also really appreciate any advice about:

1. What to practice alongside LearnCpp?

2. When to start LeetCode/problem solving?

3. Beginner → intermediate → advanced project ideas?

4. Other resources worth using?

5. Common mistakes or inefficient ways of learning C++?

6. A good roadmap for becoming genuinely confident in C++?

And one final question: At what point would you consider someone proficient enough in C++ to confidently list it under the Skills section of their resume, especially when applying for internships or entry-level positions? What should they realistically be able to do on their own?

Basically, if you were starting C++ again today, knowing what you know now, what path would you follow?

I've been trying to assign a function with a bool as the return to a std::map so I can eventually get around having a big switch statement. I am having issues getting it working though. If anyone has any suggestions that would be appreciated.

Here's a snippet of the code: https://pastebin.com/hTnaDXF3

Trying to assign it directly causes this error: Error (active) E0349 no operator "=" matches these operands

operand types are: std::function<bool ()> = bool () candidate function template "std::function<_Fty>::operator=(std::reference_wrapper<_Fx> _Func) [with _Fty=bool ()]" failed deduction function "std::function<_Fty>::operator=(std::nullptr_t) [with _Fty=bool ()]" does not match because argument #1 does not match parameter candidate function template "std::function<_Fty>::operator=(_Fx &&_Func) [with _Fty=bool ()]" failed deduction function "std::function<_Fty>::operator=(std::function<_Fty> &&_Right) [with _Fty=bool ()]" does not match because argument #1 does not match parameter function "std::function<_Fty>::operator=(const std::function<_Fty> &_Right) [with _Fty=bool ()]" does not match because argument #1 does not match parameter

The second line I was trying to use causes this error: Exception thrown at 0xCCCCCCCC

​

I started learning C++ a while ago from various YouTube channels, but they only really helped me with the theory.

I watched Apna College, Bro Code, and CodeWithHarry.

However, I'm still struggling with the syntax, let alone building the logic. I want to learn practically what do you guys recommend?

Hello y'all.

First some quick background. I have been tooting along the tutorials available on the learncpp.com website. I wanted to pick it up and work on some personal projects. So far so good.

To the point. While going through these tutorials, I've had an aching concern in the back of my mind, and I'm hoping I'm in the right place to find the correct expectation of the situation.

The question:

Am I going to end this tutorial with applicable knowledge, or will this be a situation where the tutorials will leave me with some decent fundamentals but little to actually work with?

And a followup question:

If the answer is the latter, what is a good place to get that "in the jungle" knowledge? Are there good resources for that sort of thing? Do I just hang and engage in this sub? What's a good place to get the practical side of things figured out?

I deeply appreciate any insight on this matter. You all have a good day.

Note 1: the current plan is to go through this tutorial then bone up on some tangential materials (Blender, UE, etc.) then go from there.

Note 2: I have a buddy who plans to learn this stuff too to collaborate. It will be a good while before they're caught up though.

I’ve been learning to write SIMD recently but I’m a bit fuzzy on when I would rely on compiler vs doing it myself

On one hand the compiler doing it saves a lot of code/hassle and it can likely do a good job

But if my application is something performance critical do I want to rely on the whims of the compiler or should that be baked into the application logic itself with manually written SIMD?

I did find that there is a flag you can pass and it will dump out which loops it did/didn’t vectorize which is handy

I guess I’m wondering what’s the typical practice for high performance c++ applications?

Do they write their own or rely on compiler?

Recently, I began some work trying to improve my build speeds for debug builds.

I adopted mold, and built a fully static clang executable with mimalloc and llvm libc with very aggressive optimizations.

I managed to achieve %20 speedup over my previous clang which had -O3 but not much else.

I'm planning to use pgo + bolt to gain last bits of performance I can get.

The problem I have, is that I don't know what a good workload for clang would be to use BOLT.

Any recommendations?

I have 1.5 YOE as a C++ backend engineer, I am confused about my next path, I see the options below, please suggest

1. Pivot to AI, building RAG applicants, LLM apis, MCP, python

2. Stay in C++ backend, DSA + System Design

3. Game development, Vulkan, openGL

4. CUDA, drivers

5. switch to embedded C++ , RTOS, suggest path resources for this

6. EDA domain C++, suggest and resources for this

7. Target tech agnostic SDE roles focused on DSA system design interviews of

8. C++ computer networking roles, TCP/IP, communication protocols, socket programming

I am already upskilled in AI SDLC claude, Copilot, Codex

Please suggest which of above paths to focus

I am making a tui libary where all the different things that can render are called widget like text,box, flex container, progress bar, etc.

I was using inheritance for this and all because all the container widget, multi or single child container had like lot of things common and the widgetTree contains the root widget

Each widget need two function
Layout and render ( or setRectFor child or children because render is same for most parents ) and to solve this, I did need polymorphism for this.

But the problem came later when I need to change layout ( because it wouldnt work for some widget ) and I had to rewrite all the widget,multichildwidget,singleChildWidget which means I have to rewrite all other widget as well

then later I need to change the implementation on how layout is done again, got to do rewrite

then later came scroll container, to make it effiencent I had to change things as well, had to do the rewrite

I got tried of this and now want to use composition instead of inheritance and never want to deal with it again ( I know this happened because of premature optimization where I saw widget with multiple children have lot of same things and most widget having a lot of same things )

Due to that, I am doing a rewrite again :_( but this time, I can make the code more modular.

But I got stuck on widgetTree, how do you get a tree if all the node dont have the same type?

I asked gpt but it said to use node with void* which I dont want to use because we got unique pointer and stuff to avoid new and malloc

The other option is union but that would mean all widget would have the size of the biggest widget which I dont want to use.

Then there is varient, I dont knwo much of this but I looked into it in cherno's video and geeksforgeeks page on this and turns out, it is just union but you know which type it is using. I am currently thinking this

I just can't find a way to do the tree effiency without polymorphism.

I am looking for someone to give me a mock interview on c++ internals, system design, and architecture. Specifically modern c++.

Is anyone available to help?

Im working on a project which requires alot of ui stuff and its in the terminal, so i started using ftxui. I went over the docs and they were great but they just skimmed through the basic stuff, they didnt even mention some of the components. Ive just been stuck for 2 days trying to get this working. Going through the src code, examples... nothing really works and idk what to do