C++20: Reaching for the Aims of C++ - Bjarne Stroustrup - CppCon 2021 | Summary and Q&A

TL;DR

Bjarne Stroustrup shares insights on the evolution of the C++ programming language, including its origins, key principles, and current and future developments.

Key Insights

• 🎯 Key insights from the content:
• C++ has evolved and grown over the years, maintaining stability and coherence while also embracing change and innovation.
• The initial aims of C++ included efficient hardware usage, managing complexity, and supporting both hardware and abstraction.
• Compatibility with C was important but also brought challenges, such as type checking and linking consistency.
• Abstraction and generality were essential ideals in C++ design, allowing for flexible and efficient code.
• The introduction of RAII (Resource Acquisition Is Initialization) was a significant development in managing resources and preventing leaks.
• Templates and generic programming have played a major role in C++, allowing for parameterization and flexibility in coding.
• Error handling, concurreny, and parallelism are ongoing challenges that require ongoing progress and improvement in C++.
• The C++ Core Guidelines provide guidance for modern C++ coding practices, emphasizing type safety, efficiency, and maintainability.

Transcript

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Questions & Answers

Q: Why did Bjarne Stroustrup invent C++ and what were its initial aims?

Bjarne Stroustrup invented C++ to build a distributed system efficiently and manage complexity. The initial aims were to combine the benefits of low-level hardware control with high-level abstractions, while providing tools for building systems beyond what existing languages offered.

Q: How did C++ evolve and change over time?

C++ evolved to maintain compatibility, improve type checking, and introduce features like operator overloading, generics, object-oriented programming, and lambdas. Stroustrup acknowledges the challenges of compatibility and the need for the language to adapt and grow over the years.

Q: How does C++ balance stability with innovation?

C++ balances stability with innovation by defining a subset and superset approach. It extends the language with libraries to address modern needs while retaining compatibility and avoiding breaking existing code. This approach allows for gradual improvement and gives developers access to new features while maintaining stability for older codebases.

Q: What are the key challenges in error handling and how does C++ address them?

Error handling in C++ is a complex topic, with various alternatives like exceptions, error codes, and contracts. The language has primarily used exceptions to separate error handling code from mainline code, ensuring resource management and minimizing error propagation. The challenge lies in finding the right balance between error handling strategies while preserving reliability and performance.

Q: What is the significance of features like coroutines and parallel algorithms in C++?

Coroutines and parallel algorithms are important features in addressing the challenges of concurrency and parallelism. Coroutines allow for simplified asynchronous code, while parallel algorithms enable efficient computation across multiple cores. These features contribute to the management of complexity and optimization in modern C++ code.

Q: Will there be a third edition of Stroustrup's "The C++ Programming Language" book?

Bjarne Stroustrup plans to release a third edition of "The C++ Programming Language" book, but the timing is uncertain. He is considering whether to wait until the outline of C++23 is known, as he wants to include up-to-date features like module support and improved coroutines in the book.

Q: How does C++ address the challenge of static type checking?

C++ tackles the challenge of static type checking by enforcing type rules, avoiding implicit violations, and supporting strong, static type checking. Concepts, introduced in C++20, further enhance type checking capabilities by enabling the specification of requirements for template arguments and improving code reliability and maintainability.

Q: Are there any features that Bjarne Stroustrup would like to ban or change in C++?

Bjarne Stroustrup doesn't have the power to ban or change features in C++. However, he acknowledges that some features, like implicit conversions between floating-point numbers and characters, could be improved. He also believes that the syntax and weight of certain aspects, such as template syntax, could be simplified and made more accessible.

Q: Why did Bjarne Stroustrup invent C++ and what were its initial aims?

Bjarne Stroustrup invented C++ to build a distributed system efficiently and manage complexity. The initial aims were to combine the benefits of low-level hardware control with high-level abstractions, while providing tools for building systems beyond what existing languages offered.

Summary & Key Takeaways

• Bjarne Stroustrup reflects on the history and evolution of the C++ programming language, addressing questions on its purpose and whether it has changed over time.

• He discusses the early days of C++, its design goals, and the challenges faced, such as maintaining compatibility and addressing type checking issues.

• Stroustrup emphasizes the importance of abstraction, efficiency, and strong static type checking in C++, and how these principles have shaped the language over the years.