C++ Vector of class objects
I have a class called Movie with the following private data members:
private:
string title_ ;
string director_ ;
Movie_Rating rating_ ;
unsigned int year_ ;
string url_ ;
vector<string> actor_;
It also contains the following copy constructor:
Movie::Movie(Movie& myMovie)
{
title_ = myMovie.title_;
director_ = myMovie.director_;
rating_ = myMovie.rating_;
year_ = myMovie.year_;
url_ = myMovie.url_;
actor_ = myMovie.actor_;
}
When I try to create a vector of this c开发者_如何学Class,
vector<Movie> myMovies;
and then accept all the info from a user into a temp Movie
object (myMovie1
), and then use push back:
myMovies.push_back(myMovie1);
I get the following error:
1>c:\program files (x86)\microsoft visual studio 9.0\vc\include\vector(1233) : error C2558: class 'Movie' : no copy constructor available or copy constructor is declared 'explicit'
Where am I going wrong? It seems it wants a copy constructor but I do have one defined.
My guess is that it's protesting against binding a temporary to a non-const reference. Try Movie::Movie(const Movie & myMovie)
as the signature to your copy constructor.
Code should read:
Movie::Movie(const Movie& myMovie)
{
title_ = myMovie.title_;
director_ = myMovie.director_;
rating_ = myMovie.rating_;
year_ = myMovie.year_;
url_ = myMovie.url_;
actor_ = myMovie.actor_;
}
Change copy constructor to
Movie::Movie(Movie const& myMovie)
or remove it completely - it seems that default(shallow copy) is ok in this case.
You copy constructor needs to be like this:
Movie::Movie(const Movie& myMovie)
The const
is needed for the compiler to find it.
The elements that go in a vector
must meet the "copy constructible" requirement; that is, they must have a copy constructor available. Now, is your copy constructor private or protected?
In C++11, a vector
can also take objects that are movable, although they still need to be copyable if you want to copy the vector
.
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