Declare a Result

// Declare to C a Result with a happy value of intptr_t
CXX_DECLARE_RESULT_SYSTEM(result_int, intptr_t)

// Save oneself typing out CXX_RESULT_SYSTEM(result_int) all the time
typedef CXX_RESULT_SYSTEM(result_int) result;

// Our custom C enum
enum c_enum
{
  c_enum_not_found,
  c_enum_bad_argument
};

// Make a custom status code domain for this C enum
CXX_DECLARE_RESULT_SYSTEM_FROM_ENUM(result_int,                                // The C Result type declared above
                                    c_enum,                                    // The C enum we wish to wrap
                                    "{74ceb994-7622-3a21-07f0-b016aa705585}",  // Unique UUID for this domain
                                    // Mappings of C enum values to textual description and semantic equivalances to generic codes
                                    {c_enum::c_enum_not_found, "item not found", {errc::no_such_file_or_directory}},
                                    {c_enum::c_enum_bad_argument, "invoked wrong", {errc::invalid_argument}})

// Make helper macros
#define SUCCESS(v) CXX_MAKE_RESULT_SYSTEM_SUCCESS(result_int, (v))
#define FAILURE(v) CXX_MAKE_RESULT_SYSTEM_FROM_ENUM(result_int, c_enum, (v))