我收到有关枚举的错误（我认为）

Question

I'm testing code remotely on a Solaris machine through SSH Secure Shell using c++. Not sure of what version anything is; Solaris, the c++/compiler, etc. (and don't know how to find out through SSH Secure Shell)...

This code:

#include <iostream>
#include <string>
#include <cstdlib>
#include <errno.h>

using std::cout;
using std::cin;
using std::string;


enum STR_TO_INT_STATUS { SUCCESS, OVERFLOW, UNDERFLOW, INCONVERTIBLE };

STR_TO_INT_STATUS str_to_int( int&, char const*, int );


int main()
  {
   int num;
   string str;
   STR_TO_INT_STATUS code;

   cout << "\nEnter a string containing numbers: ";

   cin >> str;

   code = str_to_int( num, str.c_str(), 0 );

   if( code == OVERFLOW || code == UNDERFLOW )
     cout << "\nThe number was out of int's range\n\n";
   else if( code == INCONVERTIBLE )
          cout << "\nThe string contained non-number characters\n\n";
        else if( code == SUCCESS )
               cout << "\nThe int version of the string is: " << num << "\n\n";
  }


STR_TO_INT_STATUS str_to_int( int &i, char const* s, int base )
  {
   char *end;
   long l;
   errno = 0;

   l = strtol( s, &end, base );

       if( ( errno == ERANGE && l == LONG_MAX ) || l > INT_MAX )
         return OVERFLOW;

       if( ( errno == ERANGE && l == LONG_MIN ) || l < INT_MIN )
         return UNDERFLOW;

   if( *s == '\0' || *end != '\0' )
     return INCONVERTIBLE;

   i = l;

   return SUCCESS;
  }

compiles and works fine... as you can see, it converts a string entered by the user into an int...

But when modified like so:

#include <iostream>
#include <string>
#include <cstdlib>
#include <errno.h>
#include <limits>
#include <cmath>

using std::cout;
using std::cin;
using std::string;
using std::numeric_limits;


int size_of( int ); //------------------------------------------------- :62

enum STR_TO_INT_STATUS { SUCCESS, OVERFLOW, UNDERFLOW, INCONVERTIBLE };

STR_TO_INT_STATUS str_to_int( int&, char const*, int ); //------------- :84


int main()
  {
   int num;
   string str;
   string dummy;
   STR_TO_INT_STATUS code;

   system( "clear" );

   cout << "\nint's max limit: "
        << numeric_limits<int>::max()
        << "\nint's min limit: "
        << numeric_limits<int>::min()
        << "\n\nnumber of digits in the largest int: "
        << size_of( numeric_limits<int>::max() )
        << "\nnumber of digits in the smallest int: "
        << size_of( numeric_limits<int>::min() );

   cout << "\nEnter a string containing numbers: ";

   cin >> str;

   code = str_to_int( num, str.c_str(), 0 );

   if( code == OVERFLOW || code == UNDERFLOW )
     cout << "\nThe number was out of int's range\n\n";
   else if( code == INCONVERTIBLE )
          cout << "\nThe string contained non-number characters\n\n";
        else if( code == SUCCESS )
               cout << "\nThe int version of the string is: " << num << "\n\n";

   cout << "Press enter key to continue...";

   getline( cin, dummy );

   system( "clear" );

   return( 0 );
  }


int size_of( int num )
  {
   int length = 0;

   num = ( int )fabs( num );

   if( num == 0 )
     length = 1;
   else
     while( num > 0 )
       {
        length++;

        num /= 10;
       }

   return( length );
  }

STR_TO_INT_STATUS str_to_int( int &i, char const* s, int base )
  {
   char *end;
   long l;
   errno = 0;

   l = strtol( s, &end, base );

   if( ( errno == ERANGE && l == LONG_MAX ) || l > INT_MAX )
     return OVERFLOW;

   if( ( errno == ERANGE && l == LONG_MIN ) || l < INT_MIN )
     return UNDERFLOW;

   if( *s == '\0' || *end != '\0' )
     return INCONVERTIBLE;

   i = l;

   return SUCCESS;
  }

I get the following compile errors:

int_limits.cpp:16: error: expected identifier before numeric constant
int_limits.cpp:16: error: expected `}' before numeric constant
int_limits.cpp:16: error: expected unqualified-id before numeric constant
int_limits.cpp:16: error: expected `,' or `;' before numeric constant
int_limits.cpp:16: error: expected declaration before '}' token

I've looked for spelling errors, tried moving the location of the enum line around... I dunno what in the world is going on.

Any help with this issue would be GREATLY appreciated!

Answer 1

The include of cmath is defining preprocessor constants OVERFLOW as 3 and UNDERFLOW as 4. So the line declaring the enum becomes (if there are no other constants):

enum STR_TO_INT_STATUS { SUCCESS, 3, 4, INCONVERTIBLE };

which, of course is not valid syntax.

Answer 2

I think it's the following line:

int size_of( int );

...should be something more like:

int sizeOfInt = size_of( int );

edit

I just compiled it on my machine and it's your OVERFLOW definition... #define's are evil!

Try this:

enum STR_TO_INT_STATUS { STR_TO_INT_SUCCESS, STR_TO_INT_OVERFLOW, STR_TO_INT_UNDERFLOW, STR_TO_INT_INCONVERTIBLE};

Answer 3

My guess is that either <limits> or <cmath> have defines for one or more of SUCCESS , OVERFLOW , UNDERFLOW , INCONVERTIBLE , which causes your enum identifiers to be converted to "numeric constants", which in turn would cause the errors that you are seeing.

You don't see them in the first version because you didn't include those headers.

Simple way to check: Try renaming the enum identifiers.

Answer 4

enum STR_TO_INT_STATUS { SUCCESS, OVERFLOW, UNDERFLOW, INCONVERTIBLE };

Perhaps on of the enumerators like SUCCESS was already previously defined. Try using SUCCESS_TEST or something to verify this.

Edit

Another way to verify this is to compile the code with the -E option, this shows the preprocessor output. For example: gcc -E main.cpp