Question

我正在使用c ++通过SSH Secure Shell在Solaris机器上远程测试代码。不知道什么版本是什么; Solaris，c ++ /编译器等（并且不知道如何通过SSH Secure Shell查找）...

此代码：

#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;
  }

编译并正常工作......如您所见，它将用户输入的字符串转换为int ...

但是当像这样修改时：

#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;
  }

我收到以下编译错误：

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

我一直在寻找拼写错误，尝试移动枚举线的位置......我不知道世界上发生了什么。

对此问题的任何帮助都将非常感激！

Answer 1

cmath的包含将预处理器常量OVERFLOW定义为3，将UNDERFLOW定义为4.因此声明枚举的行变为（如果没有其他常量）：

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

当然是无效的语法。

Answer 2

我认为这是以下几行：

int size_of( int );

......应该更像是：

int sizeOfInt = size_of( int );

修改

我刚刚在我的机器上编译它，这是你的OVERFLOW定义... #define是邪恶的！

试试这个：

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

Answer 3

我的猜测是<limits>或<cmath>定义了SUCCESS，OVERFLOW，UNDERFLOW，INCONVERTIBLE中的一个或多个，这会导致您的枚举标识符转换为“数字常量”，这反过来会导致您看到的错误。

您在第一个版本中没有看到它们，因为您没有包含这些标题。

简单的检查方法：尝试重命名枚举标识符。

Answer 4

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

也许已经定义了SUCCESS之类的枚举器。尝试使用SUCCESS_TEST或其他东西来验证这一点。

修改

验证这一点的另一种方法是使用-E选项编译代码，这显示了预处理器输出。例如：gcc -E main.cpp

我收到关于枚举的错误（我认为）

4 个答案:

修改