Mastering Type Erasure in C++23 A Macro-Free Approach for Cleaner Code

Antoine Morrier's article discusses a method for implementing type erasure in C++ without the use of macros, addressing criticisms of macro usage in programming. He presents a C++23-compliant solution that utilizes features such as deducing this, along with structuring a lightweight and flexible type erasure system that allows for the definition of actions (like drawing) associated with different types (such as circles). The article details the design of a MethodTrait to retrieve function signatures, hold function pointers, and properly invoke them. It highlights a dual storage pattern for the concrete type and function pointers, promoting a cleaner and more efficient coding experience while aiming for future optimizations.

Key Points:

• Objective: Implement C++ type erasure without macros, while improving code clarity.
• C++23 Features: Utilizes deducing this for more flexible function signatures.
• MethodTrait Structure: Facilitates the retrieval of method signatures and pointers; uses template specialization.
• Erased Class: Inherits from action methods, supports function pointer storage and object storage via std::any.
• Invoker Implementation: Allows calling methods based on their type using compile-time computations to select function pointers.
• Future Plans: Articles planned on optimizations, performance enhancements, and alternatives to std::any.
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