C++26 Introduces `std::indirect` Type, Enhancing PImpl Idiom

The PImpl idiom is a well-known design pattern frequently used in C++ programming. It is primarily employed to hide implementation details and reduce compilation dependencies. This idiom helps to improve compilation times and maintain binary compatibility for libraries. The upcoming C++26 standard is set to introduce a significant new feature to the language. This new addition is the `std::indirect` type, designed for specific use cases. The `std::indirect` type is intended to provide a standardized and safer way. It aims to simplify the implementation of the PImpl idiom within C++ projects. This new type offers a more direct and robust approach for managing opaque pointers. It could streamline code and reduce common pitfalls associated with manual PImpl implementations. The inclusion of `std::indirect` marks an evolution in C++ best practices and language features.