Vector to Array - Robin Savonen Söderholm - Meeting C++ 2025 скачать в хорошем качестве

Vector to Array - Robin Savonen Söderholm - Meeting C++ 2025

Robin shows how to preserve compile time allocations with std::vector into an std::array in constexpr context in C++ in his lightning talk from Meeting C++ 2025. This talk presents a C++20 technique for converting dynamic, heap-allocated data structures into static, compile-time constants suitable for constrained embedded environments. The speaker, motivated by porting a real-time audio cabinet emulator from a Raspberry Pi to a Raspberry Pi Pico, faced the challenge of an algorithm that produces a `std::vector` whose final size is not trivially known. The solution leverages the `constexpr` capabilities of `std::vector` in C++20. By making the vector-generating function `constexpr` and its parameters template arguments, the entire computation is shifted to compile-time. This allows for the creation of a `std::array` with the exact size and contents of the computed vector, completely eliminating the need for runtime dynamic memory allocation. A more generic refinement using a lambda is also presented.