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Making function call complex to protect license check in main()
I’m building a C++-based CLI tool and using a validateLicense() call in main() to check licensing:
int main(int argc, char argv) {
LicenseClient licenseClient;
if (!licenseClient.validateLicense()) return 1;
}
This is too easy to spot in a disassembled binary. I want to make the call more complex or hidden so it's harder to understand or patch.
We’re already applying obfuscation, but I want this part to be even harder to follow. Please don’t reply with “obfuscation dont works” — I understand the limitations. I just want ideas on how to make this validation harder to trace or tamper with.
https://redd.it/1kjadwv
@r_cpp
Looking for C++ Hobby Project Ideas: Performance-Intensive
Hi r/cpp,
I’m a C++ developer working full-time on a large C++ project that I absolutely love.
I spend a ton of my free time thinking about it, adding features, and brainstorming improvements. It’s super rewarding, but I don’t control the project’s direction and the development environment is super restrictive, so I’m looking to channel my energy into a personal C++ hobby project where I have 100% control and can try out newer technologies.
Problem is: creativity is really not my forte. So I come to you for help.
I really like performance-intensive projects (the type that make the hardware scream) —that comes not from feature bloat, but rather from the nature of the problem itself. I love diving deep into performance analysis, optimizing bottlenecks, and pushing the limits of my system.
So, here are the traits I’m looking for, in bullet points:
- Performance-heavy: Problems that naturally stress CPU/GPU (e.g., simulations, rendering, math-heavy computations).
- CUDA-compatible: A project where I can start on CPU and later optimize with CUDA to learn GPU programming.
- Analysis-friendly: Something where I can spend time profiling and tweaking performance (e.g., with NVIDIA Nsight or perf).
- Solo-scale: Something I can realistically build and maintain alone, even if I add features over months.
- "Backend focused": it can be graphics based, but I’d rather not spend so much time programming Qt widgets :)
I asked Grok and he came up with these ideas:
- A ray tracer
- A fractal generator
- A particle system
- A procedural terrain generator
I don’t really know what any of those things are, but before I get into a topic, I wanted to ask someone’s opinion. Do you have other suggestions? I’d also love to hear about:
- Tips for learning CUDA as a beginner in a hobby project.
- Recommended libraries or tools for performance-heavy C++ projects.
- How you manage hobby coding with a full-time job.
Thanks in advance for any ideas or advice! Excited to start something new and make my hardware cry. 😄
https://redd.it/1kj6nxf
@r_cpp
Use Brace Initializers Everywhere?
I am finally devoting myself to really understanding the C++ language. I came across a book and it mentions as a general rule that you should use braced initializers everywhere. Out of curiosity how common is this? Do a vast majority of C++ programmers follow this practice? Should I?
https://redd.it/1kik584
@r_cpp
Constexpr optional and trivial relocation
https://quuxplusone.github.io/blog/2025/05/08/siren-song-2-optional/
https://redd.it/1kicv53
@r_cpp
C++23 finally lets us solve the const view problem (or I don't know a better name for it)
https://blog.maycontaincode.com/2025/05/c23-finally-lets-us-solve-const-view.html
https://redd.it/1kicf3w
@r_cpp
Factoid: Each class template instantiation costs 1KiB - Clang Frontend
https://discourse.llvm.org/t/factoid-each-class-template-instantiation-costs-1kib/86189
https://redd.it/1ki9cpl
@r_cpp
Strong enum -- disable staticcast to enumeration
Has there been any consideration to have a way to prevent static cast from arbitrary integers to an enumeration?
If there was a way of saying the value of a variable was limited to the specified values:
* Better type checking
* Better code generation
​
#include <utility>
enum class A { A1, A2, A3 };
int foo(A const a){
switch(a) {
case A::A1:
return 1;
case A::A2:
return 2;
default:
std::abort();
}
}
int bar()
{
return foo(staticcast<A>(5));
}
https://godbolt.org/z/d3ob6zfxa
Would be nice to not have to put in the default so we still would get warnings about a missing enum value. The default suppresses:<source>:6:11: warning: enumeration value 'A3' not handled in switch
Wild idea
Constructor that checks against the value, sort of like gsl::not_null, once the enum is constructed you never have to check again.
enum class A { A(int)=default; A1, A2 };
https://redd.it/1ki7kf7
@r_cpp
CLion Is Now Free for Non-Commercial Use
https://blog.jetbrains.com/clion/2025/05/clion-is-now-free-for-non-commercial-use/
https://redd.it/1khte4m
@r_cpp
Practicing latest and greatest C++ features
With growing compiler support for the latest standards, I'm looking for tutorials and examples, and possibly code exercises (with textbook solutions) to practice the new features
AFAIK, learncpp.com doesn't cover the latest features
Any other recommendations?
https://redd.it/1khoa4z
@r_cpp
For now I am going to go implement this non generically to test If I am onto something or if I am wasting my time.
https://redd.it/1khdkgz
@r_cpp
Numerical Relativity 105: Smashing neutron stars together like its 2002
https://20k.github.io/c++/2025/05/07/nr105.html
https://redd.it/1kha6ea
@r_cpp
unique_ptr kind of sucks, we can make it better with a light wrapper
https://godbolt.org/z/jGP14avbv
https://redd.it/1kh4pr5
@r_cpp
Great starting point for C++ projects using CMake
https://www.youtube.com/embed/WwcNQwuW6mg
https://redd.it/1kgy9q9
@r_cpp
CLion Is Now Free for Non-Commercial Use
https://blog.jetbrains.com/clion/2025/05/clion-is-now-free-for-non-commercial-use/
https://redd.it/1kgvthq
@r_cpp
I made a Tetris Clon and I'd love some feedback
Not long ago I started to code, but recently I found C++ and it was love at first sight. This is my first "big" C++ project and I'd love some feedback so I can become a better C++ programmer. Thanks beforehand! :D
https://redd.it/1kgni16
@r_cpp
Started C++, have no idea how to start
as title say, i have no idea what is the appropriate way to start c++, as I want to learn programming in practical way. Currently I am reading C++ Primer book on the Basics. but now I want to create something but can't figure out how. Can anyone provide an resource that provide practical use of c++.
https://redd.it/1kj83o0
@r_cpp
Accelerating Your Inner Loop with Visual Studio and GitHub Copilot
https://youtu.be/rub8BEZwC28
https://redd.it/1kinb3x
@r_cpp
Does this look professional?
Hi everyone,
I'm trying to learn on my own how "corporate-coding" should be done. I'm very interested in learning the best practices for modularity, efficiency while respecting the SOLID principles. I had a C++ course during university but none of the modern C++ logic was actually tought (coding style, etc).
I'm learning by myself moving semantics + OOP.
In order to improve, by having a scientific background, I'm creating a small C++ library (supposed to be expandable) for resolving partial differential equations.
You can find the link to my repo here: **PDE\_SOLVER**
I'm here to learn any advice from you. I know some other OOP which could come handy on such library, as Builder pattern and Facede Pattern for making it more easy to use (let the library to the major of the initializations you see on main.cpp).
Am I using moving semantic right? Did I get it?
Thanks!
https://redd.it/1kifeyx
@r_cpp
Cppscript: A C++-like language compiling to TypeScript, aiming for production readiness (also my PhD project!)
https://github.com/Harsha-Bhattacharyya/Cpps.git
https://redd.it/1kibwdq
@r_cpp
How to get a graphics library
Hello. I am a simple python-cel. Whenever I wanted to use a library I would simply import it then go on with my life. Due to some unfortunate circumstances I have been needing to use cpp lately. Even more unfortunately I need to use a graphics library, either sdl2 or sfml. However I have no clue how on earth I'm supposed to use either of these libraries in visual studio or anything else no matter how many tutorials I've watched. I have realized it's pointless to try and figure out something from the middle, so what resources can I use to understand the nitty gritty about vs and cpp libraries.
https://redd.it/1ki8pxw
@r_cpp
Python to CPP? or just start?
Hello folks!I am very interested in Learning C++. The main reason is its use cases in these careers : Game programming and Embedded systems/ firmware. I am a Graphic designer and a complete outsider. Here's what I want to know :
How do I go about learning C++?
Is learning cpp for game programming different from learning for embedded (keeping the hardware aspect separate) ?
Some research online suggests that I need to learn a beginner friendly language like python and then learn Cpp. The analogy was it's like learning to drive an automatic before manual...hence a leaner curve... Is this true?
What are your suggested resources for learning cpp? I prefer video over text.
Also, If you know of any communities like a slack group, discord etc for cpp learners or any programming language newbs please let me know.Thanks in advance!
https://redd.it/1ki8r2q
@r_cpp
OOPS in CPP
I have attended an interview few months back. There they have asked a question - “ what is a copy constructor “ ? I have studied OOPS and everything but that was the first time u heard of that name. Felt very dumb. I want to know if there are any books which talks about all the OOPS advanced which should atleast teach me all concepts that are out there ?
https://redd.it/1khwlwe
@r_cpp
C++ Project Assessment
Hi, i have been learning c++ for like 8 months now, and like 3 weeks ago i started developing this project that i am kinda proud of, i would like to get assessment and see if my project is good enough, and what can i improve, i originally posted this on r/cpp but it got deleted for some reason. project link : https://github.com/Indective/TaskMasterpp please don't take down the post this time
https://redd.it/1khouox
@r_cpp
C++26: constexpr exceptions
https://www.sandordargo.com/blog/2025/05/07/cpp26-constexpr-exceptions
https://redd.it/1khkg2t
@r_cpp
Generic inspection of tail padding seems possible in C++ 26 with reflection.
Hello guys, this is a little bit of a showcase and a question at the same time. Using the experimental reflection compiler on compiler explorer, I've written a very short example implementing something I've been trying to do in our current versions of C++.
Essentially, before reflection, it was impossible to inspect the padding of an arbitrary type T in a template like this. I was just experimenting with this as a possible optimization for a container I've been writing which seems very performance sensitive to the size of an integer field that must be included with each data member. Basically, I wanted to place this integer field in the padding bytes of any type T, given T has enough padding bytes left over. I'm quite sure the logic in my example is not sound for types with other sizes or alignments than shown, but I was just trying to write a proof of concept.
Right now in the example, I am using a union of the type T and a struct of the integer prefaced with arbitrary storage of size equal to sizeof(T) - padding. For a 16 byte type with 4 bytes of tail padding, the union would contain that type alongside a struct of size (sizeof(T) - padding + sizeof(uint32_t)), so the struct would be 16 bytes long, the same size as the type, placing the uint32_t at offset 12 of the type, making it take up the padding bytes. I'm quite sure this is somehow UB, but I've heard reflection is also capable of defining new types, hopefully allowing me to define a new type, the same as the type T, but with the uint32_t field included inside, avoiding the undefined behavior.
I'm not sure if this optimization actually results in any performance improvement on my container yet, as I've been trying to find a way to implement it generically, so if anybody knows of a way to do similar in current C++ then please let me know.
Realistic Time Estimate for Programming Assignment
I was recently given three tasks by a recruiter and was told they typically take around 6 hours to complete. However, as someone who’s just finishing my degree, they seem quite extensive and more time-consuming than that. Do you think it's reasonable to expect these to be done in 6 hours?
# Task 1: Partial File Matching Using Incremental Hashing
You are provided with two file paths: `fileAlpha` and `fileBeta`. Determine if the contents of `fileAlpha` fully match the **beginning** of `fileBeta`.
The files may be large, potentially larger than system memory, so they must be processed in segments.
* Use the provided function to calculate incremental checksums: uint32\_t UpdateHash(const char\* chunk, size\_t size, uint32\_t prevHash);
* You can only process up to 1024 bytes per call of `UpdateHash` (`size <= 1024`).
* `prevHash` should be initialized to `0` for the first block and passed into each successive call.
* If `fileBeta` is larger than `fileAlpha`, it should still return `true` **as long as the starting bytes match exactly** with all bytes of `fileAlpha`.
Implement the following function:
bool BeginsWithSameContent(const std::string& fileAlpha, const std::string& fileBeta);
# Task 2: Maximum Radius with Unique Tags
You are given a set of labeled coordinates in 2D space. Each point consists of an `(x, y)` coordinate and a `label` string. Some points may share the same label but have different positions.
Implement a function that computes the largest possible radius `R` of a circle centered at the origin `(0,0)` such that **only one point of each label is inside the circle**.
A point is considered *inside* the circle if the Euclidean distance from `(0,0)` is **strictly less than** the radius.
struct LabeledPoint {
float x;
float y;
std::string label;
};
float FindMaxUniqueRadius(const std::vector<LabeledPoint>& data);
# Task 3: Concurrent Client Message Handler
Design the server-side logic for handling a message-based system where clients communicate with a central service. A singleton class named `DataLink` is used to mediate messages. Clients initiate communication, and the server must manage multiple connections.
# Message Types:
* `INIT` – first message to open a session
* `CLOSE` – final message to end session
* `PING` – used by clients to stay active
* `NOTE` – contains up to 256 characters of user data
* `DENY` – sent by server to reject a connection
* `FAIL` – sent by server to terminate session due to error
Each message contains:
* A `clientID` (automatically provided by `DataLink`)
* A `messageType`
* A `sequenceIndex` (starting from 1 and increasing by 1 with each client message)
* For `NOTE`, a `text` field (≤256 chars)
Clients must send at least one message every 30 seconds (`ACTIVITY_WINDOW`), even if it's just a `PING`.
Server should:
* Track active sessions
* Allow only `MAX_USERS` concurrent clients (respond `DENY` to excess clients)
* Enforce correct sequence: must begin with `INIT` and end with `CLOSE`
* Check that `sequenceIndex` increases correctly (otherwise send `FAIL`)
* Respond with `FAIL` if a client is inactive for too long
* Print all `NOTE` messages to the standard output
# Define:
* The interface of the `DataLink` class:
* struct Msg { uint32\_t clientID; enum class Kind { INIT, CLOSE, PING, NOTE, FAIL, DENY } type; uint32\_t sequenceIndex; std::string text; // only valid if type == NOTE }; class DataLink { public: static DataLink& Instance(); Msg\* Receive(uint32\_t waitMs); // waits for a message or returns null void Transmit(const Msg& msg); // sends message back to client };
* Then implement the core server logic in a class `SessionManager`, which continuously:
* Waits for and processes client messages
* Handles errors and timeouts
* Limits concurrent clients
* Validates sequence rules
https://redd.it/1kh834k
@r_cpp
Need someone on youtube that teaches OOP in c++
hi im a student studying c++, i need someone on youtube thats good at teaching oop in c++
https://redd.it/1kh2f79
@r_cpp
CLion Debugging Not Working - Breakpoints Not Hit on macOS M1 Pro
I'm struggling with debugging my C++ project in CLion on my macOS M1 Pro (ARM64). I'm working on a project that involves AES encryption/decryption using OpenSSL, and my breakpoints aren't being hit when I try to debug with LLDB. Here are the details:
* **Setup**: CLion with CMake 3.26.4, ninja build tool, cc/c++ compilers, and LLDB 16.0 (bundled).
* **Project**: Built in Debug mode (CMAKE\_BUILD\_TYPE=Debug), with run/debug
* **Issue**: Breakpoints aren't hit. The build output shows "ninja: no work to do," suggesting no rebuild occurs.
* **Tried So Far**:
* Set working directory to project root .
* Rebuilt project with **Build > Rebuild Project**.
* Verified files exist.
* Checked console for errors (none obvious).
* **Observation**: The program might be exiting early due to file issues, but I'm not sure.
Has anyone else faced this issue with CLion debugging on an M1 Mac? Any suggestions on how to fix this would be greatly appreciated! Let me know if you need more details (e.g., CMakeLists.txt, full code).
https://redd.it/1kgww02
@r_cpp
I made a Tetris Clon with C++ and I would love some feedback
I started coding not long ago, but recently I found C++ and it was love at first sight. This is my first "big" C++ project and I would like to get feedback so I can code better and better. Thanks before hand! :D
https://github.com/ARTempest/Tetris-
https://redd.it/1kgnfdl
@r_cpp
Taskflow v3.10 released! Thank you for your support!
https://taskflow.github.io/taskflow/release-3-10-0.html
https://redd.it/1kgm9q3
@r_cpp