Automatic marshaling of C++ functions into SQL user functions

marshal.cc

#include "SQLiteWrapper.h"

std::string reverse(std::string str) {
  std::reverse(str.begin(), str.end());
  return str;
}

int main(void) {
  static const char reverse_name[] = "reverse";
  sqlite::createFunction<reverse_name>(&reverse);
  
  static const char db_name[] = ":memory:";
  using db = sqlite::Database<db_name>;
  static const char select_query[] = "select reverse(?1)";
  auto fetch_row = db::query<select_query>("hello world!");
  std::string_view str;
  while (fetch_row(str)) {
    std::cout << str << std::endl;
  }
}

Output: !dlrow olleh