C++ RVO and std::move performance impact

Why don’t more C++ developers talk about Return Value Optimization (RVO)? This optimization has existed in C++ since 1997, yet many developers still assume returning objects is expensive. Let’s take a simple case. A function creates an object and returns it: MyClass Myfun() { return MyClass obj; } Without optimization, you might imagine this happening: • create obj inside Myfun() • copy it when returning to main() • destroy the local object That sounds like extra work, right? Here’s the interesting part. Modern C++ compilers apply Return Value Optimization (RVO). Instead of: create → copy → destroy The compiler simply constructs the object directly in the caller’s memory. So the object is effectively created inside main() from the start. No extra copy. No unnecessary destruction. A subtle optimization — but one that makes returning objects cheap and idiomatic in C++. Small compiler optimizations like this are why understanding how C++ actually works under the hood matters. Did you learn about RVO early, or much later in your C++ journey? #CPP #SoftwareEngineering #Programming #SystemsProgramming #Developers

Reading through the upcoming C++26 changes, I ran into an example that captures a recurring tension in modern C++ very well. // Predicate: select monsters that are currently dead. auto dead = [](const auto& monster) { return monster.isDead(); }; // Problematic pattern: // We iterate over a filtered view and then mutate the same property // that the filter depends on. for (auto& monster : monsters | std::views::filter(dead)) { monster.bringBackToLife(); // Undefined behavior } At first glance, this feels surprising. C++26 proposes this form instead: // Treat the range as input-only before filtering. // This avoids the multi-pass assumptions that make the previous code invalid. auto dead = [](const auto& monster) { return monster.isDead(); }; for (auto& monster : monsters | std::views::as_input | std::views::filter(dead)) { monster.bringBackToLife(); // OK } What makes this interesting is not just the rule itself, but the feeling it creates. When a language needs an extra adapter to make a very intuitive loop valid, it raises a deeper design question: is the programmer doing something exotic, or is the abstraction exposing machinery that leaks too much into everyday code? Examples like this still make C++ feel as if correctness sometimes depends less on what the code means, and more on whether you remembered the exact operational contract of the pipeline. This is one of those moments where modern C++ feels incredibly powerful, but also slightly at odds with how humans naturally expect code to behave. #cpp #cpp26 #programming #softwareengineering #systemsprogramming

C++26 will introduce 𝗿𝗲𝗳𝗹𝗲𝗰𝘁𝗶𝗼𝗻 and we are all very excited about it. But there currently exist many 𝗹𝗶𝗯𝗿𝗮𝗿𝗶𝗲𝘀 that offer reflection for C++, how is that possible? Most of them use the __𝗣𝗥𝗘𝗧𝗧𝗬_𝗙𝗨𝗡𝗖𝗧𝗜𝗢𝗡__ compiler trick. This trick has been around for quite a while in modern compilers like GCC, Clang and MSVC and it’s very useful for this situation. It basically prints a string with 𝗳𝘂𝗻𝗰𝘁𝗶𝗼𝗻 𝘀𝗶𝗴𝗻𝗮𝘁𝘂𝗿𝗲 information at compile time. With some 𝘁𝗲𝗺𝗽𝗹𝗮𝘁𝗲 𝗺𝗲𝘁𝗮𝗽𝗿𝗼𝗴𝗿𝗮𝗮𝗺𝗶𝗻𝗴 techniques (like really heavy machinery) it is actually possible to achieve a functional reflection for pre-C++26 standards. It’s limited, but kind of works for lot of situations. The trick itself is 𝗻𝗼𝘁 𝗳𝘂𝗹𝗹𝘆 𝗽𝗼𝗿𝘁𝗮𝗯𝗹𝗲 and must be used carefully, as every compiler produces different output formats. Luckily, some developers have already squeezed this into heavily templated, ready-to-use libraries that do all the hard work for you. C++26 reflection will likely replace these approaches with a 𝘀𝘁𝗮𝗻𝗱𝗮𝗿𝗱𝗶𝘇𝗲𝗱 𝘀𝗼𝗹𝘂𝘁𝗶𝗼𝗻. Until then, this is what “reflection” in modern C++ looks like in practice. reflect-cpp: https://lnkd.in/ejaVevUa magic enum: https://lnkd.in/eK4tPPPe #cpp #c #cplusplus #modernc #moderncpp #cpp17 #cpp20 #cpp23 #cpp26 #coding #code #programming #reflection #array #pointer #arithmetic #typesafety #tech #future #embedded #software #firmware #cleancode #distributed #systems #compiler #gcc #clang #msvc

Here is an article about Type Punning in C/C++. What it is and why we should care as developers doing low-level engineering It discusses a possible case that could fail under the umbrella of optimisation in production code. Feel free to share your thoughts! #LowLevel #EmbeddedSystems #UndefinedBehavior #StrictAliasing #SoftwareEngineering

Hello, C++ developers. [Post 13] ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ TOPIC: Copy Elision and Return Value Optimization (RVO) Master compiler optimizations that eliminate copy/move operations entirely by constructing objects directly in their final destination. What this carousel covers: → Copy elision principle - construct → copy → destroy becomes just construct in place → RVO (Return Value Optimization) - returning prvalues, mandatory in C++17 → NRVO (Named RVO) - returning named locals, optional but common → C++17 guaranteed copy elision - prvalue expressions bypass copy/move entirely → std::move prevents NRVO - never use std::move on return statements → Multiple return paths - usually prevent NRVO optimization → Non-copyable types - work with RVO (C++17+), not with NRVO unless compiler applies it → Automatic move fallback - if NRVO fails, compiler uses move instead of copy → Real-world measurements - construct only vs construct + move comparisons Key insights: ◆ C++17 RVO is mandatory for prvalues - return Object() always elides, no copy/move possible ◆ NRVO is optional - return local_var may or may not elide, compiler-dependent ◆ std::move on return prevents RVO/NRVO - forces move when elision would have occurred ◆ Return by value is efficient - trust the compiler, don't use out-parameters for optimization ◆ Multiple return paths block NRVO - compiler can't determine single object address ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Note: LinkedIn compresses carousel images. For best experience, download the PDF or pinch-zoom on mobile. #CPlusPlus #CPP #RVO #NRVO #CopyElision #CompilerOptimization #CPP17 #Programming #SoftwareEngineering #PerformanceOptimization #ZeroCopy #ModernCPP #TechEducation #DeveloperLife #CodeOptimization #Prvalue #ReturnValueOptimization #TechnicalExcellence #AdvancedCPP #CompilerMagic

🚀 5 Modern C++ Practices That Will Save You Hours of Debugging After reviewing hundreds of C++ codebases and mentoring dozens of developers, I’ve noticed the same costly patterns repeating. The good news? Most are easy to fix once you know what to look for. Here are 5 practical tips that will immediately improve your C++ code – whether you're on C++17, C++20, or already experimenting with C++23. 1. Prefer std::unique_ptr over raw new/delete Not just for safety – it makes ownership explicit and eliminates whole classes of memory leaks. Your future self (and your code reviewers) will thank you. 2. Use constexpr and consteval aggressively Move computation to compile time when possible. It’s not just about performance – it catches errors earlier and makes intent crystal clear. 3. Stop writing raw loops <algorithm> + lambdas often produce clearer, safer, and sometimes faster code. std::transform, std::find_if, and std::accumulate are your friends. 4. Embrace std::optional and std::variant Replace output parameters (bool + reference) and error-prone unions. Your function signatures become self-documenting. 5. Turn on all warnings and treat them as errors -Wall -Wextra -Wpedantic -Werror (or the MSVC equivalent). This single change catches more bugs than any linter. Bonus: Run your tests under AddressSanitizer and UndefinedBehaviorSanitizer weekly. The hidden issues you’ll find are often the ones that would have exploded in production. I’ve written a deeper dive with code examples and before/after comparisons – here down you can view it and dowload it. What’s one C++ practice that changed how you write code? Let’s discuss below. 👇

💥 Stop the NullReferenceException — C# Nullable Reference Types NullReferenceException is the #1 runtime crash in C#. And 99% of the time — it's completely preventable. Here's how to eliminate it 💥 The Problem string name = GetName(); // could be null int len = name.Length; // 💥 CRASH at runtime You won't know it's null until production blows up. ✅ Enable Nullable in C# 8+ Add this to your .csproj: <Nullable>enable</Nullable> Now the compiler warns you before the crash happens. Bugs caught at compile time, not runtime. ❓ string? vs string string name = "Ahmad"; // guaranteed non-null ✅ string? name = null; // explicitly says "this can be null" 🛡️ Null-Safe Operators — Use These Daily user?.Name // null if user is null — no crash name ?? "Anonymous" // fallback if null name ??= "Default" // assign only if null ⚠️ Null Forgiving Operator — Handle with Care string name = GetName()!; // tells compiler "trust me" Use this ONLY when you are 100% certain the value is not null. Otherwise you're just hiding the problem. 💡 Enabling nullable annotations is one of the easiest wins in any C# codebase. It takes 5 minutes to enable and saves hours of debugging. Have you enabled nullable in your projects? #CSharp #DotNet #BackendDevelopment #SoftwareEngineering #CleanCode #Programming #ASPNET

#Day-6 of 30 Days/30 Posts challenge. 👉 upgrading the C++ advanced concepts.... 💢 C++ is powerful—but only if you truly understand how memory works. When I first started with C++, I focused on syntax and logic. But everything changed when I began to understand memory management. 🧠 Why Memory Management Matters In C++, you are in control of: Allocation Deallocation Ownership 👉 That control is powerful… but also risky. 🔹 Stack vs Heap ▶️ Stack Memory ▫️ Fast, automatic ▫️ Managed by compiler ▫️ Limited size ▶️ Heap Memory ▫️ Dynamic, flexible ▫️ Managed by developer ▫️ Requires manual cleanup int a = 10; // Stack int* p = new int; // Heap 🔹 The Problem If not handled properly: ❌ Memory leaks ❌ Dangling pointers ❌ Undefined behavior 🔹 The Solution (Modern C++) 👉 Use Smart Pointers ▫️ unique_ptr → single ownership ▫️ shared_ptr → shared ownership ▫️ weak_ptr → avoids circular references 🔹 My Key Learning Understanding memory management taught me: 👉 Who owns the data? 👉 When should memory be released? 👉 How to write safe and efficient code? 🚀 Final Thought C++ doesn’t manage memory for you— it gives you the power to do it right. And once you understand that, you stop just writing code… and start engineering systems. Still learning, but building stronger fundamentals every day 💡 #CPP #MemoryManagement #ModernCPP #SoftwareEngineering #Programming #LearningJourney

Can a C/C++ program compile or run without main()? This is one of those questions that looks simple… but reveals how compilers, linkers, and OS actually work. Short answer: ✔ Compile — YES Run — NO (as a standalone program) 🔹 Why can it compile? Because the compiler only translates your code into object files. No main()? No problem — it just creates .o files. 🔹 Why can’t it run? Because the OS needs a starting point. That starting point is usually main() No main() = No entry point = No executable 🔹 But here’s where it gets interesting… There are real-world cases where main() is NOT required 👇 ✔ Shared Libraries → Used by other programs ✔ Frameworks (Arduino, GUI) → Framework defines main() ✔ Embedded Systems → Custom entry points (_start) ✔ Low-level systems / kernels → No standard flow Compiler translates code Linker connects everything OS decides where execution begins You don’t always need main() to build code… But you definitely need an entry point to run it.

Can a C/C++ program compile or run without main()? This is one of those questions that looks simple… but reveals how compilers, linkers, and OS actually work. Short answer: ✔ Compile — YES Run — NO (as a standalone program) 🔹 Why can it compile? Because the compiler only translates your code into object files. No main()? No problem — it just creates .o files. 🔹 Why can’t it run? Because the OS needs a starting point. That starting point is usually main() No main() = No entry point = No executable 🔹 But here’s where it gets interesting… There are real-world cases where main() is NOT required 👇 ✔ Shared Libraries → Used by other programs ✔ Frameworks (Arduino, GUI) → Framework defines main() ✔ Embedded Systems → Custom entry points (_start) ✔ Low-level systems / kernels → No standard flow Compiler translates code Linker connects everything OS decides where execution begins You don’t always need main() to build code… But you definitely need an entry point to run it.