Unable to use member function inside a class - c++

Question

I am currently learning about classes and am having a problem in my class implementation file.
In my class header/specification file Book.h , I have the public member function setPages.
#ifndef BOOK_H
#define BOOK_H
#include <string>
#include "Author.h"
#include "Publisher.h"
class Book
{
private:
std::string _title;
std::string _edition;
int _pages;
int _copyrightYear;
Author _author;
Publisher _publisher;
public:
Book (std::string title, Author author, Publisher publisher)
{_title = title; _author = author; _publisher = publisher;}
void setPages (int pages);
void setCopyYear (int copyrightYear);
void setEdition (std::string edition);
std::string getTitle () const;
std::string getEditon () const;
int getPages () const;
int getCopyYear () const;
Author getAuthor () const;
Publisher getPublisher () const;
};
#endif
In my Book.cpp implementation file I have
#include <string>
#include "Author.h"
#include "Publisher.h"
#include "Book.h"
void Book::setPages (int pages)
{
_pages = pages;
}
I keep getting the error that Book is not a classname or namespace but I don't see what I've done wrong. I included my Book header file and checked to make sure everything was spelled correctly in the class. I've done the same thing in my other classes and it is working so I don't see why this isn't.
Any help appreciated thanks.
Here is Publisher.h and Author.h
#ifndef PUBLISHER_H
#define PUBLISHER_H
class Publisher
{
private:
std::string _name;
std::string _address;
std::string _phoneNumber;
public:
Publisher (std::string& name)
{_name=name;}
void setAddress (std::string address);
void setNumber (std::string phoneNumber);
std::string getAddress () const;
std::string getNumber () const;
bool operator==(std::string name)
{
if (_name == name)
return true;
else
return false;
};
#endif
and Author.H
#ifndef AUTHOR_H
#define AUTHOR_H
class Author
{
private:
std::string _name;
int _numberOfBooks;
public:
Author(std::string& name)
{_name = name;}
void setNumOfBooks (int numberOfBooks);
int getNoOfBooks () const;
bool operator==(std::string _name)
{
if (this->_name == _name)
return true;
else
return false;
}
};
#endif

Answer 1

Until #ahenderson decides to turn his comments into an answer:
bool operator==(std::string name) in "Publisher.h" is missing a brace in your example. is that actually in your code or a copy and paste error?
bool operator==(std::string name)
{
if (_name == name)
return true;
else
return false;
Oops, no brace here!

Answer 2

Suggestion: Simplify your operator== method:
The expression _name == name will already return true or false. No need to put it into an if clause that returns true or false.
Try this:
bool operator==(const std::string& name)
{
return (_name == name);
}
In the above example, the expression is evaluated and the result is returned, directly.
Also, you may run into compiler issues if your variables begin with an underscore, '_'. Change your naming convention so this issue doesn't raise its ugly head. Two common practices are to append a suffix, name_, or prefixing with something like m_name.