constexpr has come a long way since its introduction in C++11. Back then, constexpr functions were extremely restricted and could essentially contain only a single return statement. C++14 relaxed those restrictions, allowing local variables, loops, and multiple statements. C++20 was another major milestone, bringing support for constexpr dynamic allocation, enabling types such as std::string and std::vector to become usable in constant evaluation, and allowing constexpr virtual functions. C++23 further relaxed the rules by permitting static local constexpr variables and try blocks inside constexpr functions. C++26 continues the trend, adding support for exception handling during constant evaluation and several other improvements…