This document exists in multiple languages - thanks to the translators !
Teaching C++ is a hard task, for students as well as for teachers. This manifesto intends to ensure that this task is not made unintentionally harder for both parties, by providing up-to-date best practices for teaching.
- Too many courses take the approach of presenting C++ on the same level of abstraction than C. This is severely misguided.
- C++ programs are written against the C++ abstract machine, not your classroom's CPUs, and compilers will optimize code with the assumptions of the abstract machine in mind.
- C++ allows for arbitrarily high levels of abstractions, with generally no runtime penalty for optimized code, if either inlining or LTO are leveraged.
- Expressive C++ Coding Challenge Results
- Value semantics.
- Especially over object semantics of languages such as Java / C#.
- Prefer automatic storage to dynamic storage (stack variables over
new/shared_ptr/unique_ptrwhenever possible).
- Const-correctness.
- Ownership and RAII, resource management.
- Zero-cost abstractions.
- Generic programming and how to leverage the type system to provide maximal compile-time guarantees on your program.
- In particular, not doing at run-time what can be done at compile time.
- C++ authors and designers have created the C++ Core Guidelines, in order to show what is the best practice, in a language with 40 years of legacy baggage.
- Collaborative Collection of C++ Best Practices
- ISO rules mandata that the only valid standard at a given point in time is the last one. We don't build new houses with electric plugs from 50 years ago.
- C++ has a three years release cadence : by the time the students are on the job market, what was considered avant-garde during their classes will be mainstream.
- It is not necessary to use non-released standards, but it can be interesting to at least look at them - that's the standards which will be in effect when the students are out of school !
- Windows : use msys2 with the latest clang, gcc, or an MSVC recent enough to support motion 4.
- Ubuntu or Debian : if a recent distribution is not available, use the packages from https://apt.llvm.org/
- Mac : use a recent macOS with the latest Xcode, or install the latest gcc or llvm from Homebrew if macOS cannot be upgraded.
- Because it is not. By the own word of its creator, it is a multi-paradigm language.
- Fun fact : C++ is a fairly advanced functional language, thanks to type-level computations and some level of dependent typing (non-type template parameters).
- C++ can be leveraged to study almost the whole history of programming, so let's leverage that and provide nice examples to our students.
- No "C/C++" : https://www.youtube.com/watch?v=YnWhqhNdYyk
- No C-with-classes : just teach C or Java if you really want to do that.
- No "Java/C++". Hint : if you are writing
new std::string, there is something wrong. - No
-fno-exceptions: exceptions are a core part of C++. They give all their meaning to RAII, and except on 32-bit Windows are faster on the happy path than error codes.- It's easier to learn to not use exceptions if you already know them, than to learn to use exceptions if you don't.
- No
conio.h/iostream.h/graphics.h/ whatever DOS-era API you can find.
- Multiple classical development patterns were over the years integrated in various programming language, either as language or library features.
- Closed polymorphism : visitor pattern -> now can be done with std::variant
- Strategy pattern : std::function
- Long story short : it does not work in the general case.
- is
volatileuseful with threads ? - Use atomics.