🚀 go-pugleaf

bcc063@casbah.acns.nwu.edu (UNLISTED) wrote:

>i just finished installing the libg++ library for c++ and i want to test the
>compiler to see if it is working. when i try to compile the following little
>test file using gcc,
>i get these errors:
>	collect2: ld returned 2 exit status
>	ld: Undefined symbol
>	  String::length(void)
>	  String::set_to(char *)
>	  String::read(void)

>what do these errors mean i did or didn't do? 
>(i'm new at c++)
>below are the files...

>/* this is the beginning of file String.h */
>const int max_string_length = 128;
>class String{
>public:
>  void set_to(char*);
>  int length();
>  int read();
>  void print();

>private:
>  char text[max_string_length+1];
>};
>/* this is the end of file String.h */

You have only "declared" the member functions, set_to, length, read
and printf.  You must "define" them as well.  If they are simple (one
liners) then this can be done within the class instead of the
declarations. . .

#include <stdio.h>
#include <string.h>

class String
{ char text[max_string_length+1);

public:
  void set_to(char *str) { strncpy(text, str, sizeof text); }
  int length() { return strlen(text); }
  void read() { gets(text); }
  void printf() { puts(text); }
};

Simple member functions like these are implicitly "inline" so they
incur no overhead above directly accessing a structure member in C.

Regards,
Andy Robb.

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