# Quantifying Accidental Complexity An empirical look at teaching and using C++ Herb Sutter ## Why complexity matters We’re “paying taxes” all the time Productivity Correctness and quality Tooling catalog, classify, and count ## Fred Brooks: Complexity ## Essential complexity Inherent in the problem, present in any solution ## Accidental complexity PUSH Artifact of a specific solution design first 638 rules catalogued 533 language 25 essential + minimal 147 ‘essential’ + improvable 361 accidental + improvable 

## Algorithmic Complexity Amir Kirsh & Adam Segoli Schubert ___  © All rights reserved ## Why this talk? ## Why this jpg) ## Algorithmic Complexity Performance is the name of the game ## Algorithmic Complexity It’s actually about something BIGGER than just performance ## Algorithmic Complexity What's BIGGER than performance? ## Algorithmic Complexity What's BIGGER than just performance? ## Scalability # Computational Complexity Computational Complexity or simply Complexity of an algorithm is the amount

## Amortized $ \mathcal{O}(1) $ Complexity Andreas Weis CppCon 2024 $$ \blacksquare f\in\mathcal{O}(g)\iff\exists C>0.\exists x_{0}>0.\forall x>x_{0}:|f(x)|\leq C\cdot|g(x)| $$ Child's What is amortized complexity? The Design and Analysis of Computer Algorithms  What is amortized complexity?  # What is amortized complexity? # AMORTIZED COMPUTATIONAL COMPLEXITY $ ^{*} $ ROBEY EMORE

sapien, sed malesuada diam lacus eget erat. ## Local phase Validate small neighborhoods with high-complexity algorithms. Describe neighborhood interactions coarsely in small tables. ## Global phase Collate Collate the small tables into a big table of interactions. Validate the interactions with low-complexity algorithms. Indirect caller's interface fits many functions Function interface fits a specific

fashioning of the complex conceptual structures that compose the abstract software entity, and accidental tasks, the representation of the abstract entities in programming languages and the mapping of big gains in software productivity have come from removing artificial barriers that have made the accidental tasks inordinately hard, such as severe hardware constraints, awkward programming languages, lack lack of machine time. How much of what software engineers now do is still devoted to the accidental, as opposed to the essential?” ## Agile Abstract “Therefore it appears that the time has come to address

predictability and consistent behavior (once pattern is recognized) Enables system scaling (in size and complexity) ## Symmetry (def): Agreement in dimensions due to proportion and arrangement  probing of your components and subsystems will identify changes to lower system complexity • Does each step express clear purpose? • If yes, is more obvious for enforcing step semantics obvious for where a desired action should be placed • Are the steps guaranteed to occur? • If yes, complexity is reduced (edge cases are removed) • Can a step be “empty” (e.g., “do nothing” or “default” behavior

remove if(v.begin(), v.end(), pred); • v.erase(remove_if(v.begin(), v.end(), pred)); • Quadratic complexity vec.erase(iter) loop ☐ • Invalidating iterators while looping ☐ • Skipping elements while looping better • spans are implicitly constructible from arrays and vectors • Avoids ownership confusion, accidental pointer arithmetic span → span; span → □ span • Shallow const

remove_if(v.begin(), v.end(), pred); • v.erase(remove_if(v.begin(), v.end(), pred)); • Quadratic complexity vec.erase(iter) loop • Invalidating iterators while looping • Skipping elements while looping better • spans are implicitly constructible from arrays and vectors • Avoids ownership confusion, accidental pointer arithmetic • span ☐ span; span ✗ span • Shallow const

lighting, animation principles, etc. 3D creation software such as Blender have an added technical complexity and jargon associated with the underlying technologies. Terms like UV maps, materials, shaders selecting objects that are in a different mode than the current one. Note This option can prevent accidental mode changes, such as when you’re trying to select a bone in Pose Mode to animate it, but instead 9c1df1a.png) Example of a node group. Grouping nodes can simplify a node tree by hiding away complexity and reusing repetitive parts. Conceptually, node groups allow you to treat a set of nodes as though

application of multiple hardware-related parallel and communication technologies leads to the increasing complexity of porting between different architectures, and deploying and optimizing HPC applications can be policies. The measurement result can be used for measurement and appraisal: • Measurement: Detects accidental or malicious modifications to files, with local or remote attestation. • Appraisal: Measures a has a bigger impact. When PID 1 is faulty, the OS must be restarted to rectify the fault. • High complexity: systemd becomes the de facto standard for PID 1, introducing many new concepts, tools, and extended