Method message

src/fl/stl/expected.h:94–97

@brief Get error message (only meaningful if !ok())

    /// @brief Get error message (only meaningful if !ok())
    const char* message() const FL_NOEXCEPT {
        auto* err = mData.template ptr<ErrorInfo<E>>();
        return err ? err->message.c_str() : "";
    }

    /// @brief Get value (only valid if ok() == true)
    /// @warning Undefined behavior if called when !ok()