How can I use a class with the same name from another namespace in my class?
- by Beau Simensen
I have two classes with the same name in different namespaces. I want one of these classes to reference the other class. The reason is that I am migrating to some newer code and I want to update the old code to simply pass through to the newer code.
Here is a super basic example:
namespace project {
namespace legacy {
class Content {
public:
Content(const string& url) : url_(url) { }
string url() { return url_; }
private:
string url_;
};
}} // namespace project::legacy;
namespace project {
namespace current {
class Content {
public:
Content(const string& url) : url_(url) {}
string url() { return url_; }
private:
string url_;
}} // namespace project::current;
I expected to be able to do the following to project::legacy::Content, but I am having trouble with some linker issues. Is this an issue with how I'm trying to do this, or do I need to look more closely at my project files to see if I have some sort of weird dependency issues?
#include "project/current/Content.h"
namespace project {
namespace legacy {
class Content {
public:
Content(const string& url) : actualContent_(url) { }
string url() { return actualContent_.url(); }
private:
project::current::Content actualContent_;
};
}} // namespace project::legacy;
The test application compiles fine if I try to reference an instance of project::current::Content but if I try to reference project::current::Content from project::legacy::Content I get an:
undefined reference to `project::current::Content::Content(...)`
UPDATE
As it turns out, this was a GNU Autotoolset issue and was unrelated to the actual topic. Thanks to everyone for their help and suggestions!
