generate error messages functions

errors_generator.cpp

#include <string>

#include <fmt/format.h>
#include <fmt/printf.h>

namespace details
{
#define ERROR_MESSAGES(X) \
        X(DivByZero) \
        X(NumOverflow) \
        /****/

#define DEFINE_MESSAGE_ID(X) X,    
   enum class MessageId : int {
   Invalid = -1,         
   ERROR_MESSAGES(DEFINE_MESSAGE_ID)
   };
#undef DEFINE_MESSAGE_ID

struct literal
{
    template<size_t N>
    constexpr literal(const char (&str)[N]) : data{str}, size{N-1}{}
    const char* const data;
    const size_t size; 
};

constexpr const literal allMessages[] = {
   // todo: move to include file
   "Divizion by zero {:d}/{:d}",
   "Numeric overflow for expression {}", 
};

} // namespace details

#define DEFINE_FORMAT_FUNC(X) \
template<typename... Args>  \
auto format ## X (Args&&... args) { \
    return fmt::format( \
  [] { \
    struct str : fmt::compile_string { \
      using char_type = char;           \
      constexpr operator fmt::string_view() const {\
          using namespace details; \
          return {allMessages[(int)MessageId::X].data, allMessages[(int)MessageId::X].size}; \
      }} result;  \
    return result; \
    }(),     \
    std::forward<Args>(args)...);\
}

ERROR_MESSAGES(DEFINE_FORMAT_FUNC)

#define COMPILE_ERRORS 0

int main()
{
#if COMPILE_ERRORS
   fmt::print( formatDivByZero(2, 1.0) );
   //fmt::print( formatDivByZero(2) );
   //fmt::print( formatNumOverflow(1,2,3,4));
#else
   fmt::print( formatDivByZero(2,0) );
   fmt::print( formatNumOverflow("111111111111111111111111111111 * 10"));
#endif
}