Bjarne Stroustrup

• Introduced b a high school student

• Stability and evolution
• “A tour of C++”, 2nd edition
• Distinguish betwee what’s lega and what’s effective
• Better tool support, eg C_+ core Guidlines
• C++: principled and eclectic
• C++ a general purose programming language for the defn, impl and use of lightweight abstractions
• “We don’t really like C++ but is it the only thing that works”
• C++ high level aims
• Evolutionary (stable, gradual adoption)
• Make simple things simple
• Zero-overhead principle
• Aim high: change the way we design and implement software and we think
• Key C++ “Rules of thumb”
• Static type sisteym build-in and user-defined
• Value and referenc semantics
• Direct use of machine and operating system resources
• Layers of abstraction
• The Onion principle:The more layers you peel off, the more you cry
• Systematic and generl resource management (RAII)
• Construct/destructor paris
• Every resource must have an owner; don’t use built-in pointers (T*) to manage
• Support composition of software from separatelhy developed parts
• Modules
• Support for generic programming
• write code that works for types tat meet abstract requirements
• requiremensts are defined as concepts
• Support fo compile-time programming

• const_expr

• Move computaton from run-time to compile-time
• Support for object-oriented programming
• Still useful and popular
• Need reference semantics
• Don’t need run-time; use static resolution (variant)
• See

  overloaded

  which do not ake it into c++20

• Concurrency through libraries supported by intrinsics
• mutex, RAII
• atomics
• C++ is tunable and evolves
• Always measure
• Things work in combination
• Library design is language desing; language design is library design
• cppreference.com/w/cpp/libs
• Chrono
• You have to raise the level abstraction for tools to enforce type and resource-safe C++
• These rules are about 40 years old
• C++2o the best approximation of C++’s ideals (so far)
• The future
• C++23:
• Completes C++20
• Plus: standard modules, library support for coroutines, executors and netowrking
• Maybe: static reflection, pattern match
• Questions
• Something about co_await and threads
• How to deal with legacy code
• In new code use modern features
• Either try and encapsulate
• Need more tooling
• What feature most affected c++11:
• const_expr
• basic support for concurrent programming
• What feature most affected c++20:
• concepts will make generic much simpler, elegant, adn useful
• modules should improve our compile speeds (5-10 times?). Major advantage is from cleaning up your code.
• Not pay for things you use. However someone has to pay $ for implementing these features
• It’s better to put the burden on implementers then users. 50,000 users for 5-10 implementors
• Are there plans to add features to enforce ownership checks at compile time?
• Use static enforced coding guideless to enforce “good” coding standards instead of “legal” codes.
• Cyril from Bloomberg. Would you discourage use of runtime polymorphism?
• Does someting really need hierarchis and runtime/dynamic types