C++ First Principles Design

Add new operations to C++ classes

• Visitor
• std::visit

Implement specific functionality

• Strategy

What should be done to execute piece of work

• Command

Integrate incompatible interfaces

• Adapter

Monitoring thousands of endpoints

• Observer

Decoupling from implementation

• Bridge

Virtual functions performance overhead

• CRTP
• C++20 concepts

Do you really need inheritance

• Type Erasure

General Class Design Tips

• Prefer non-member, non-friend functions - better encapsulations
• Prefer minimality - single purpose classes
• Prefer algorithms which scale well with additional data
• Do not optimize prematurely
• Avoid implicit conversions
• Sequence - prefer vectors
• Allocate memory the right way
• Globals, shared data, static objects increase coupling and reduce scope for parallelism
• Use message queues to communicate instead of shared global data
• Compile at the highest warning level

References

• First Principles While Designing C++ Applications - Prabhu Missier - CppCon 2025
• https://github.com/pcodex