# Modern C++ Programming

## C++03 / C++11 / C++14 / C++17 / C++20 / C++23 / C++26 This *open-access* course is directed at those who are already familiar with C and object-oriented programming towards a proficiency level of C++ programming. The course covers the basics of C++ programming and moves on to advanced C++ semantics and concepts. **Key features**: - *Free and frequently updated* - *26 lectures, 1800+ slides* - Include the *last language standard* concepts and features - *Practical teaching*: non-verbose, short structured descriptions associated with code - *Minimal code examples* for showing just a specific feature or issue without digressing - *Complementary language aspects*: tools, coding conventions, project organization, and code optimization - *Experience-based*: many aspects, examples, and problems come from real-world cases faced during my work as software engineer *If you enjoy the course or you find it useful*, please add a **Star** [![stars - Modern-CPP-Programming](https://img.shields.io/github/stars/federico-busato/Modern-CPP-Programming?style=social)](https://github.com/federico-busato/Modern-CPP-Programming) ## CHAPTERS | # | TITLE | MAIN FOCUS | | ------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------- | | **1** | [**Introduction**](01.Introduction.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/01.Introduction.html)) | History of C/C++, Areas of applications, Course introduction | | **2** | [**Preparation**](02.Preparation.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/02.Preparation.html)) | Books, How to compile, Hello world | | **3** | [**Basic Concepts I**](03.Basic_Concepts_I.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/03.Basic_Concepts_I.html)) | Type System, Fundamental types, and Operators | | **4** | [**Basic Concepts II**](04.Basic_Concepts_II.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/04.Basic_Concepts_II.html)) | Integral and Floating-point types and their arithmetic | | **5** | [**Basic Concepts III**](05.Basic_Concepts_III.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/05.Basic_Concepts_III.html)) | Entities, Enumerators, Structures, Control flow statements | | **6** | [**Basic Concepts IV**](06.Basic_Concepts_IV.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/06.Basic_Concepts_IV.html)) | Heap, Stack, Pointers, References, Const properties, Conversion operators | | **7** | [**Basic Concepts V**](07.Basic_Concepts_V.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/07.Basic_Concepts_V.html)) | Functions, Lambda expressions, Preprocessing directives | | **8** | [**Object-Oriented Programming I**](08.Object_Oriented_I.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/08.Object_Oriented_I.html)) | Class hierarchy, Constructor, Destructor, Class keywords | | **9** | [**Object Oriented Programming II**](09.Object_Oriented_II.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/09.Object_Oriented_II.html)) | Polymorphism, Operators overloading | | **10** | [**Templates and Meta-programming I**](10.Templates_I.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/10.Templates_I.html)) | Function template, Type traits, Compile-time utilities | | **11** | [**Templates and Meta-programming II**](11.Templates_II.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/11.Templates_II.html)) | Class template, SFINAE | | **12** | [**Translation Units I**](12.Translation_Units_I.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/12.Translation_Units_I.html)) | Linkage and One Definition Rule | | **13** | [**Translation Units II**](13.Translation_Units_II.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/13.Translation_Units_II.html)) | Dealing with multiple translation units and files,`#include`, Modules | | **14** | [**Code Conventions I**](14.Code_Convention_I.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/14.Code_Convention_I.html)) | Project organization, code conventions intro, entities conventions | | **15** | [**Code Conventions II**](15.Code_Convention_II.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/15.Code_Convention_II.html)) | Template, namespace, modern c++, maintainability , naming, and formatting conventions | | **16** | [**Debugging and Testing**](16.Debugging.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/16.Debugging.html)) | Execution/memory debugging, Sanitizers, Harding techniques, Unit test, Test-Driven Development | | **17** | [**Ecosystem**](17.Ecosystem.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/17.Ecosystem.html)) | Cmake, Documenting, and Other Tools | | **18** | [**Utilities**](18.Utilities.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/18.Utilities.html)) | Main `std` libraries | | **19** | [**Containers, Iterators, and Algorithms**](19.Iterators_Containers_Alg.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/19.Iterators_Containers_Alg.html)) | Containers, Iterators, Algorithms, Ranges | | **20** | [**Advanced Topics I**](20.Advanced_Topics_I.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/20.Advanced_Topics_I.html)) | Move semantics, Universal reference, Type deduction | | **21** | [**Advanced Topics II**](21.Advanced_Topics_II.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/21.Advanced_Topics_II.html)) | Error handling, C++ idioms, Smart pointers | | **22** | [**Performance Optimizations I**](22.Optimization_I.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/22.Optimization_I.html)) | Ahmdal Law, Performance bounds, Architecture concepts (ILP, SIMD, etc.), Memory hierarchy | | **23** | [**Performance Optimizations II**](23.Optimization_II.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/23.Optimization_II.html)) | Arithmetic optimizations, Memory optimizations, etc. | | **24** | [**Performance Optimizations III**](24.Optimization_III.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/24.Optimization_III.html)) | Compiler optimizations, Profiling, Benchmarking tools | | **25** | [**Software Design I**](25.Software_Design_I.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/25.Software_Design_I.html)) | Basic Concepts, Principles, Use cases | | **26** | [**Software Design II**](26.Software_Design_II.pdf) ([html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/26.Software_Design_II.html)) | Design Patterns and Idioms | ***ALL-IN-ONE BOOK***: [**modern-cpp.pdf**](modern-cpp.pdf) (could be a few commits behind), [html](https://federico-busato.github.io/Modern-CPP-Programming/htmls/modern-cpp.html) ## TOPICS IN DETAILS **[1. Introduction](01.Introduction.pdf)** * **A Little History of C/C++ Programming Languages** * **Areas of Application and Popularity** * **C++ Philosophy** * **C++ Weakness**: C++ alternatives, Why switching to a new language is hard? * **The Course** **[2. Preparation](02.Preparation.pdf)** - **Books and References** - **Slide Legend** - **What Editor/ IDE/Compiler Should I Use?** - **How to compile?** - **Hello World**: I/O Stream **[3. Basic Concepts I - Type System, Fundamental Types, and Operators](03.Basic_Concepts_I.pdf)** * **The C++ Type System**: Type categories, Type properties * **C++ Fundamental Types Overview**: Arithmetic types, Suffix and prefix, Non-standard arithmetic types, `void` type, `nullptr` * **Conversion Rules** * **`auto` Keyword** * **C++ Operators**: Operators precedence, Prefix/Postfix increment/decrement semantic, Assignment, compound, and comma operators, Spaceship operator `<=>` , Safe comparison operators **[4. Basic Concepts II - Integral and Floating-point Types](04.Basic_Concepts_II.pdf)** * **Integral Data Types**: Fixed width integers, `size_t`, `ptrdiff_t`, `uintptr_t`, Arithmetic Operation Semantics, Promotion, Truncation, Undefined behavior, Saturation Arithmentic * **Floating-point Types and Arithmetic**: IEEE Floating-point standard and other representations, Normal/Denormal values, Infinity, Not a Number (`NaN`), Machine Epsilon, Units at the Last Place (ULP), Cheatsheet, Limits and useful functions, Arithmetic properties, Special values behavior, Undefined behavior, Detect floating-point errors * **Floating-point Issues**: Catastrophic cancellation, Floating-point comparison **[5. Basic Concepts III - Entities and Control Flow](05.Basic_Concepts_III.pdf)** * **Entities** * **Declaration and Definition** * **Enumerators** * **`struct`, Bitfield, `union`** * **Control Flow**: `if` statement, `for` and `while` loops, Range-base `for` loop, `switch`, `goto`, Avoid unused variable warning * **Namespace**: Explicit global namespace, namespace alias, `using`-declaration, `using namespace`-directive, `inline` namespace * **Attributes**: `[[nodiscard]]`, `[[maybe_unused]]`, `[[deprecated]]`, `[[noreturn]]` **[6. Basic Concepts IV - Memory Concepts](06.Basic_Concepts_IV.pdf)** * **Pointers**: Pointer operations, Address-of operator `&` * **Heap and Stack**: Stack memory, `new`, `delete`, Non-allocating placement allocation, Non-throwing allocation, Memory leak * **Initialization**: Variable initialization, Uniform initialization, Array initialization, Structure initialization, Structure Binding, Dynamic memory initialization * **References** * **`Const` and Constant Expressions**: Contants and literals, `const`, `constexpr`, `consteval`, `constinit`, `if constexpr`, `std::is constant evaluated()`, `if consteval` * **`volatile` keyword** * **Explicit Type Conversion**: `static_cast`, `const_cast`, `reinterpret_cast`, Type punning, `std::bit_cast`, Uniform initialization conversion, `gls::narrow_cast` * **`sizeof` Operator**: overview, `[[no_unique_address]]` **[7. Basic Concepts V - Functions and Preprocessing](07.Basic_Concepts_V.pdf)** * **Functions**: Pass-by-value, Pass-by-pointer, Pass-by-reference, Function signature and overloading, Overloading and `=delete`, Default parameters * **Function Pointer and Function Objects** * **Lambda Expressions**: Capture list, Lambda expression and function relation, Parameter notes, Composability, Recursion, `constexpr/consteval`, `template`, `mutable`, `[[nodiscard]]`, Capture list and classes * **Preprocessing**: Preprocessors, Common errors, Source location macros, Conditional compiling macros, Stringizing operator (`#`), `#error` and `#warning`, `#pragma`, Token-pasting operator `##`, Variadic macro **[8. Object-Oriented Programming I - Class Concepts](08.Object_Oriented_I.pdf)** * **C++ Classes**: RAII idiom * **Class Hierarchy** * **Access specifiers**: Inheritance access specifiers, When use `public/protected/private` for data members? * **Class Constructor**: Default constructor, Class initialization, Uniform initialization for objects, Delegate constructor, `explicit` keyword, `[[nodiscard]]` and classes * **Copy Constructor** * **Class Destructor** * **Defaulted Constructors, Destructor, and Operators** (`= default`) * **Class Keywords**: `this`, `static`, `const`, `mutable`, `using`, `friend`, `delete` **[9. Object-Oriented Programming II - Polymorphism and Operator Overloading](09.Object_Oriented_II.pdf)** * **Polymorphism**: C++ mechanisms for polymorphism, `virtual` methods, Virtual table, `override` keyword, `final` keyword, Common errors, Pure virtual method, Abstract class and interface * **Inheritance Casting and Run-time Type Identification** * **Operator Overloading**: Overview, Comparison operator `<`, Spaceship operator `<=>`, Subscript operator `[]`, Multidimensional subscript operator `[]`, Function call operator `()`, static operator `[]` and operator `()`, Conversion operator `T()`, Return type overloading resolution, Increment and decrement operators `++`/`--`, Assignment operator `=`, Stream operator `<<`, Operator notes * **C++ Object Layout**: Aggregate, Trivial class, Standard-layout class, Plain old data (POD), Hierarchy **[10. Templates and Meta-programming I - Function Templates and Compile-Time Utilities](10.Templates_I.pdf)** * **Function Template**: Overview, Template instantiation, Templat parameters, Template parameter - default value, Overloading, Specialization * **Template Variable** * **Template Parameter Types**: Generic Type Notes, `auto` Placeholder, Class template parameter type, Array and pointer types, Function type * **Compile-Time Utilities**: `static_assert`, `using` keyword, `decltype` keyword * **Type Traits**: Overview, Type traits library, Type manipulation **[11. Templates and Meta-programming II - Class Templates and SFINAE](11.Templates_II.pdf)** * **Class Template**: Class specialization, Class template constructor * **Constructor template automatic deduction (CTAD)** * **Class Template - Advanced Concepts**: Class + Function - specialization, Dependent names - `typename` and `template` keywords, Class template hierarchy and `using`, `friend` keyword, Template template arguments * **Template Meta-Programming** * **SFINAE: Substitution Failure Is Not An Error**: Function SFINAE, Class SFINAE * **Variadic Template**: Folding expression, Variadic class template * **C++20 Concepts**: Overview, `concept` keyword, `requires` clause, `requires` expression, `requires` expression + clause, `requires` clause + expression, `requires` and `constexpr`, Nested `requires` * **Template Debugging** **[12. Translation Units I - Linkage and One Definition Rule](12.Translation_Units_I.pdf)** * **Basic Concepts**: Translation unit, Local and global scope, Linkage * **Storage Class and Duration**: Storage duration, Storage class, `static` keyword, Anonymous namespace, `extern` keywords * **Linkage of `const` and `constexpr`**: Static initialization order fiasco * **Linkage Summary** * **Dealing with Multiple Translation Units**: Class in multiple translation units * **One Definition Rule (ODR)**: Global variable issues, ODR - Point 3, `inline` functions/variables, `constexpr` and `inline` * **ODR - Function Template**: Cases, `extern` keyword * **ODR - Class Template**: Cases, `extern` keyword * **ODR Undefined Behavior and Summary** **[13. Translation Units II - Include, Module, and Namespace](13.Translation_Units_II.pdf)** - **`#include` Issues**: Include guard, Forward declaration, Circular dependencies, Common linking errors - **C++20 Modules**: Overview, Terminology, Visibility and reachability, Module unit types, Keywords, Global module fragment, Private module fragment, Header module unit, Module partitions - **Compiling Multiple Translation Units**: Fundamental compiler flags, Compile Methods - **Libraries in C++**: Static library, Build static libraries, Using static libraries, Dynamic library, Build dynamic libraries, Using dynamic libraries, Application binary interface (ABI), Demangling, Find Dynamic library dependencies, Analyze object/executable symbols **[14. Code Conventions I](14.Code_Convention_I.pdf)** * **C++ Project Organization**: Project directories, Project files, "Common" project organization notes, Alternative - “Canonical” project organization * **Coding Styles and Conventions**: Overview, Popular coding styles * **Header Files and `#include`**: `#include` guard, `#include` syntax, order of `#include`, Common header/source filename conventions * **Preprocessing**: Macro, Preprocessing statements * **Variables**: `static` global variables, conversions * **Enumerators** * **Arithmetic Types**: Signed vs. unsigned integral types, integral types conversion, Integral types: size and other issues, Floating-point types * **Functions**: Function parameters, Function arguments, function return values, Function specifiers, lambda expressions * **Structs and Classes**: `struct` vs `class`, Initialization, Braced initializer lists, Special member functions, `=default`, `=delete`, Other issues, Inheritance, Style **[15. Code Conventions II](15.Code_Convention_II.pdf)** - **`auto`** - **Templates and Type Deduction** - **Control Flow**: Redundant control flow , `if/else`, Comparison, `switch`, `for/while` - **Namespace**: `using namespace` directive, Anoymous/unnamed namespace, Namespace and class design, Style - **Modern C++ Features**: Keywords, Features, Class, Library - **Maintainability**: Code comprehension, Functions, Template and Debuction, Library - Portability - **Naming**: Entities, Variables, Functions, Style conventions, Enforcing naming styles - **Readability and Formatting**: Horizontal spacing, Pointers/References, Vertical spacing, Braces, Type decorators, Reduce code verbosity, Other issues - **Code Documentation**: Function documentation, Comment syntax, File documentation **[16. Debugging and Testing](16.Debugging.pdf)** * **Debugging Overview** * **Assertions** * **Execution debugging**: Breakpoints, Watchpoints / Catchpoints, Control flow, Stack and info, Print, Disassemble, `std::breakpoint` * **Memory Debugging**: `valgrind` * **Hardening Techniques**: Stack usage, Standard library checks, Undefined behavior protections, Control flow protections * **Sanitizers**: Address sanitizer, Leak sanitizer, Memory sanitizers, Undefined behavior sanitizer, Sampling-baed sanitizer * **Debugging Summary** * **Compiler Warnings** * **Static Analysis** * **Code Testing**: Unit testing, Test-Driven Development (TDD), Code coverage, Fuzz testing * **Code Quality**: `clang-tidy` **[17. Ecosystem - Cmake and Other Tools](17.Ecosystem.pdf)** - **CMake**: `cmake` and `ctest` - **Code Documentation**: `doxygen` - **Code Statistics**: Count lines of code, Cyclomatic complexity analyzer - **Other Tools**: Code formatting - `clang-format`, `Compiler Explorer`, Code transformation - `CppInsights`, AI-powered code completion -Local code search - `ugrep`, `ripgrep`, `hypergrep`, Code search engine - `searchcode/grep.app`, Code benchmarking - `Quick-Bench`, Font for coding **[18. Utilities](18.Utilities.pdf)** * **I/O Stream**: Manipulator, `ofstream/ifstream` * **Strings**: `std::string`, Conversion from/to numeric values, `std::string_view`, `std::format`, `std::print` * **View**: `std::span` * **Math Libraries** * **Random Number**: Basic concepts, C++ ``, Seed, PRNG period and quality, Distribution, Recent algorithms and Performance, Quasi-random * **Time Measuring**: Wall-Clock time, User time, System time * **Std Class Templates**: `std::pair`, `std::tuple`, `std::variant`, `std::optional`, `std::any`, `std::stacktrace` * **Filesystem Library**: Query methods, Modify methods **[19. Containers, Iterators, and Algorithms](19.Iterators_Containers_Alg.pdf)** * **Containers and Iterators** * **Sequence Containers**: `std::array`, `std::vector`, `std::deque`, `std::list`, `std::forward_list` * **Associative Containers**: `std::set`, `std::map`, `std::multiset` * **Container Adaptors**: `std::stack`, `std::queue`, `std::priority_queue` * **Implement a Custom Iterator**: Implement a simple Iterator * **Iterator Notes**: * **Iterator Utility Methods**: `std::advance`, `std::next`, `std::prev`, `std::distance`, Container access methods, Iterator traits * **Algorithms Library**: `std::find_if`, `std::sort`, `std::accumulate`, `std::generate`, `std::remove_if` * **C++20 Ranges**: Key concepts, Range view, Range adaptor, Range factory, Range algorithms, Range actions **[20. Advanced Topics I](20.Advanced_Topics_I.pdf)** * **Move Semantic**: `lvalues` and `rvalues` references, Move semantic, `std::move`, Class declaration semantic * **Universal Reference and Perfect Forwarding**: Universal reference, Reference collapsing rules, Perfect forwarding * **Value Categories** * **`&`, `&&` Ref-qualifiers and `volatile` Overloading** * **Copy Elision and RVO** * **Type Deduction**: Pass by-reference, Pass-by-pointer, Pass-by-value, `auto` deduction, `auto(x)`: Decay-copy * **`const` Correctness** **[21. Advanced Topics II](21.Advanced_Topics_II.pdf)** - **Undefined Behavior:** Illegal behavior, Platform specific behavior, unspecified behavior, Detecting undefined behavior - **Error Handling**: Recoverable error handing, Return code, C++ Exceptions, Defining custom exceptions, `noexcept` keyword, Memory allocation issues, Return code and exception summary, `std::expected`, Alternative error handling approaches - **Smart pointers**: `std::unique_ptr`, `std::shared_ptr`, `std::weak_ptr` - **Concurrency**: Thread methods, Mutex, Atomic, Task-based parallelism **[22. Optimization I - Basic Concepts](22.Optimization_I.pdf)** * **Introduction**: Moore's Law, Moore's Law limitations, Reasons for optimizing * **Basic Concepts**: Asymptotic complexity, Time-Memory trade-off, Developing cycle, Ahmdal's law, Throughput, Bandwidth, Latency, Performance bounds, Arithmetic intensity * **Basic Architecture Concepts**: Instruction throughput (IPC), In-Order, and Out-of-Order Execution, Instruction pipelining, Instruction-level parallelism (ILP), Little’s law, Data-level parallelism (DLP) and vector instructions (SIMD), Thread-level parallelism (TLP), Single Instruction Multiple Threads (SIMT), RISC, CISC instruction sets * **Memory Hierarchy**: Memory hierarchy concepts, Memory locality, Core-to-core latency and thread affinity, Memory ordering model **[23. Optimization II - Code Optimization](23.Optimization_II.pdf)** * **I/O Operations**: `printf`, Memory mapped I/O, Speed up raw data loading * **Memory Optimizations**: Heap memory, Stack memory, Cache utilization, Data alignment, Memory Prefetch * **Arithmetic Types**: Data types, Arithmetic operations, Conversion, Floating-point, Compiler intrinsic functions, Value in a range, Lookup table * **Control Flow**: Branhes, Branch Hints - `[[likely]]` / `[[unlikely]]`, Signed/Unsigned integers, Loops, Loop hoisting, Loop unrolling, Assertions, Compiler hints `[[assume]]/std::unreacheable()`, Recursion * **Functions**: Function call cost, Argument passing, Function inlining, Function attributes, Pointers aliasing * **Object-Oriented Programming** * **Std Library and Other Language Aspects** **[24. Optimization III - Non-Coding Optimizations and Benchmarking](24.Optimization_III.pdf)** * **Compiler Optimizations**: About the compiler, Compiler optimization flags, Floating-point optimization flags, Linker optimization flags, Architecture flags, Help the compiler to produce better code, Profile guided optimization (PGO), Post-processing binary optimizer, Polyhedral optimizations * **Compiler Transformation Techniques**: Basic transformations, Loop unswitching, Loop fusion, Loop fission, Loop interchange, Loop tiling * **Libraries and Data Structures** * **Performance Benchmarking**: What to test?, Workload/Dataset quality, Cache behavior, Stable CPU performance, Multi-threads considerations, Program memory layout, Measurement overhead, Compiler optimizations, Metric evaluation * **Profiling**: `gprof`, `uftrace`, `callgrind`, `cachegrind`, `perf` Linux profiler * **Parallel Computing**: Concurrency vs. parallelism, Performance scaling, Gustafson's Law, Parallel programming languages **[25. Software Design I - Basic Concepts (DRAFT)](25.Software_Design_I.pdf)** - **Books and References** - **Basic Concepts**: Abstraction, interface, and module, Class Invariant - **Software Design Principles**: Separation of concern, Low coupling, high cohesion, Encapsulation and information hiding, Design by contract, Problem decomposition, Code reuse - **Software Complexity**: Software entropy, Technical debt - **The SOLID Design Principles** - **Class Design**: The class interface principle, Member functions vs. free functions, namespace functions vs. class static methods - **BLAS GEMM Case Study** - **Owning Objects and Views** - **Value vs. Reference Semantic** - **Global Variables** **[26. Software Design II - Design Patterns and Idioms (DRAFT)](26.Software_Design_II.pdf)** - **C++ Idioms**: Rule of Zero, Rule of Three, Rule of Five - **Design Pattern**: Singleton, Pointer to implementation (PIMPL), Curiously Recurring Template Pattern (CRTP), Template virtual functions ### Roadmap 1. Improve Software Design Chapters 2. Build Aspects Chapter (e.g. reducing build time) ### Reporting bugs 🐛 and contributing If you find any typo, conceptual error, or section to improve, please report them by using the `issue` panel. ## Author `Federico Busato`, https://federico-busato.github.io/ - LinkedIn: [www.linkedin.com/in/federico-busato/](https://www.linkedin.com/in/federico-busato/) - Twitter: [twitter.com/fedebusato](https://twitter.com/fedebusato)