Basic compile problem

Hi All

I have the most simple situation, but I cannot compile it

I have the following files: main.C, Book.C and Book.h:

Book.h:

Code:

---

class Boek {
  public:
        Boek() ;
        ~Boek() {}
        void print() ;
} ;

---

Book.C:

Code:

---

#include "Book.h"

Book::Book() {}

void Book::print() {}

---

main.C:

Code:

---

#include "Book.h"
#include <string>
#include <iostream>

using namespace std ;

int main() {
    Book book() ;
    book.print() ;
    return 0 ;
}

---

If I compile this code like: c++ main.C Book.C
I get the following error:

Code:

---

main.C:9 error: request for member ‘print’ in ‘book’, which is of non-class type ‘Book ()()’

---

If I remove the line book.print() eveything compiles fine
Any suggestions what I do wrong here ?

Thanks a lot
LuCa

Change "Book book();" to "Book book;".

Edit: In addition to the obvious change of spelling "Book" correctly in Book.h.

If this is C++ code, why do your files end with a .c extention? It should be .cpp

I thought for c++ (linux) the convention was capital .C
So thats not true ?

LuCa

Could be, I use windows not linux so you could be right there. As long as the code works it is not a big problem

The man page for g++ says that it recognizes any of the following as C++ files:

file.cc
file.cp
file.cxx
file.cpp
file.CPP
file.c++
file.C

Personally I'd prefer .C since it's short, or .c++ since it's clear, but since most people seem to use .cpp I go along with that.

hmm, I've still problems.
Now I've add a initialization method to Book.h[code]Book(std::string t): title(t) {}[code]
However if I add the following line to main.C

Code:

---

Book book("The Code book") ;

---

I get the following error

Code:

---

main.o: In function `main':
main.C:(.text+0x1b5): undefined reference to `Book::Book(std::basic_string<char, std::char_traits<char>, std::allocator<char> >)'
main.C:(.text+0x1d0): undefined reference to `Book::~Book()'
collect2: ld returned 1 exit status
make: *** [xxxxx] Error 1

---

Any suggestions what might be the reason for this to happen ?

Thnx a lot
LuCa

> class Boek
Maybe you still can't spell Book properly.

Book is just a work I use for here :)

The strange thing is that I only get this error when I try to create a BOOK object: Book book("bla bla")
So if I do nothing with the Book class it compiles fine...

LuCa

Quote:

---

Originally Posted by luca

Book is just a work I use for here :)

The strange thing is that I only get this error when I try to create a BOOK object: Book book("bla bla")
So if I do nothing with the Book class it compiles fine...

LuCa

---

You do not seem to have constructor that accepts const char* or const std::string as a parameter

why 'const' ?

This is a linker error, which is odd since it implies that you got something right with your header.

Please post your latest Book.h, Book.C, main.C

because "bla bla" is const char*

Quote:

---

Originally Posted by vart

because "bla bla" is const char*

---

You can create a non-const std::string from a char const *. The std::string parameter is weak enough for this function.

Quote:

---

Originally Posted by QuestionC

You can create a non-const std::string from a char const *. The std::string parameter is weak enough for this function.

---

It is absolutely opposite
you can pass non-const value to the param that is declared as const.
you cannot pass the const string to the param that is not const