Compile errors with linked files in C++

Question

Edit: I've reduced a majority of the errors with the std:: prefix on string declarations. However, there seems to be a problem with a few functions, particularly the definitions of those functions who have a string as a parameter.

Edit #2: Updated my code (I DID have the std:: prefix on my function declarations, but hadn't reflected it in my post). Please see the very bottom for errors displayed when I add the std:: prefix to string parameters in the problematic functions.

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I have a header file movie.h with the following code (relevant code):

#include <string>

class Movie
{
    public:

        void addMovieName(std::string movie);
        void addLastName(std::string nameLast);
        void addFirstName(std::string nameFirst);

    private:

        string movieName,
               directorLastName,
               directorFirstName,
               directorFullName;
};

And an implementation file movie.cpp like this (relevant code):

#include "movie.h"

// addFirstName, addLastName, and addMovie name all do the same things
// so I'm only including one since they all generate the same error

void Movie::addFirstName(string nameFirst)
{
   directorFirstName = nameFirst.resize(10, ' ');
}

Upon compilation, I get the following errors:

g++ -c movie.cpp -o movie.o
movie.cpp:225: error: variable or field ‘addFirstName’ declared void
movie.cpp:225: error: ‘int Movie::addFirstName’ is not a static member of ‘class Movie’
movie.cpp:225: error: ‘string’ was not declared in this scope
movie.cpp:226: error: expected ‘,’ or ‘;’ before ‘{’ token
movie.cpp:240: error: variable or field ‘addLastName’ declared void
movie.cpp:240: error: ‘int Movie::addLastName’ is not a static member of ‘class Movie’
movie.cpp:240: error: ‘string’ was not declared in this scope
movie.cpp:241: error: expected ‘,’ or ‘;’ before ‘{’ token
movie.cpp:255: error: variable or field ‘addMovieName’ declared void
movie.cpp:255: error: ‘int Movie::addMovieName’ is not a static member of ‘class Movie’
movie.cpp:255: error: ‘string’ was not declared in this scope
movie.cpp:256: error: expected ‘,’ or ‘;’ before ‘{’ token
make: *** [movie.o] Error 1

---

Some of who have said I need to prepend std:: to the string parameters in the function definitions.

Upon doing this:

// adding std:: prefix
void Movie::addFirstName(std::string nameFirst)
{
   directorFirstName = nameFirst.resize(10, ' ');
}

---

I get the following errors. Note that I only changed it for a single function. The first errors I don't understand, whereas the rest remain the same as before.

g++ -c movie.cpp -o movie.o
movie.cpp: In member function ‘void Movie::addFirstName(std::string)’:
movie.cpp:227: error: no match for ‘operator=’ in ‘((Movie*)this)->Movie::directorFirstName = nameFirst.std::basic_string<_CharT, _Traits, _Alloc>::resize [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>](10u, 32)’
/usr/lib/gcc/i386-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/basic_string.h:485: note: candidates are: std::basic_string<_CharT, _Traits, _Alloc>& std::basic_string<_CharT, _Traits, _Alloc>::operator=(const std::basic_string<_CharT, _Traits, _Alloc>&) [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>]
/usr/lib/gcc/i386-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/basic_string.h:493: note:                 std::basic_string<_CharT, _Traits, _Alloc>& std::basic_string<_CharT, _Traits, _Alloc>::operator=(const _CharT*) [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>]
/usr/lib/gcc/i386-redhat-linux/4.1.2/../../../../include/c++/4.1.2/bits/basic_string.h:504: note:                 std::basic_string<_CharT, _Traits, _Alloc>& std::basic_string<_CharT, _Traits, _Alloc>::operator=(_CharT) [with _CharT = char, _Traits = std::char_traits<char>, _Alloc = std::allocator<char>]
movie.cpp: At global scope:
movie.cpp:240: error: variable or field ‘addLastName’ declared void
movie.cpp:240: error: ‘int Movie::addLastName’ is not a static member of ‘class Movie’
movie.cpp:240: error: ‘string’ was not declared in this scope
movie.cpp:241: error: expected ‘,’ or ‘;’ before ‘{’ token
movie.cpp:255: error: variable or field ‘addMovieName’ declared void
movie.cpp:255: error: ‘int Movie::addMovieName’ is not a static member of ‘class Movie’
movie.cpp:255: error: ‘string’ was not declared in this scope
movie.cpp:256: error: expected ‘,’ or ‘;’ before ‘{’ token
make: *** [movie.o] Error 1

Answer 1

You have not specified the correct namespace for string, string is a member of the std namespace. In this case you need to write std::string since I see no "using namespace std;" in your code.

replace:

string movieName,
       directorLastName,
       directorFirstName,
       directorFullName;

with:

std::string movieName,
            directorLastName,
            directorFirstName,
            directorFullName;

Answer 2

Why are all your private fields pointers? Storing plain ints and floats as fields is perfectly okay. Moreover, you don't need to "initialize" strings in your constructor. If you don't, their default constructors will be called automatically (strings will be empty). And why do you pad strings? Even if you need it when displaying, pad them there.

Answer 3

No one has answered the question yet, so I figured I'd just put it here myself since I figured it out. Basically, my solution was:

Use using std::string in header and implementation files.

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Secondly, the declaration:

stringOne = stringTwo.resize(some_number, ' ');

...fails because resize() is a void returning function. Replacing that with two separate statements; namely:

stringOne = stringTwo;
stringOne.resize(/* blah */);

...solves the rest of the errors. Credit to @Jesse for mentioning this in the comments.