CODEWITHSUNDEEP
c++
Jatin
Jatin

Reputation: 1997

Can we alias a class name the way we do in namespaces?

Can we alias a class name the way we do in namespaces?

For example:

namespace longname{ }
namespace ln = longname;// namespace aliasing

class LONGNAME {};
class LN = LONGNAME; // how to do class name aliasing, if allowed?

Upvotes: 26

Views: 24032

Answers (5)

DRman
DRman

Reputation: 1

I assume typedef, as others have mentioned, is the best answer. In my Project that didn't work though due to other reasons, so I had to resort to another solution:

class LN: public LONGNAME {
    //inherit ALL constructors
    using LONGNAME::LONGNAME;
}

Basically you create a child class that's identical to the parent class.
If that comes with problems I haven't noticed, feel free to correct me.

Upvotes: 0

user1810087
user1810087

Reputation: 5334

Beside the answers already provided using the keyword typedef, you also can use the keyword using since C++11. IMHO it looks more consistent regarding the aliasing.

namespace longname{ }
namespace ln = longname;// namespace aliasing

class LONGNAME {};
using LN = LONGNAME; // "class aliasing"

In addition, with using you are able to alias template classes (How to typedef a template class?) by using alias templates.

template<typename T> class LONGNAME {};
template<typename T> using LN = LONGNAME<T>; // alias template

Upvotes: 22

Alexandre C.
Alexandre C.

Reputation: 56966

Simple:

typedef LONGNAME LN;

Typedefs are used in C++ a bit like "variables which can store types". Example:

class Car
{
public:
    typedef std::vector<Wheel> WheelCollection;

    WheelCollection wheels;
};

By using Car::WheelCollection everywhere instead of std::vector<Wheel>, you can change the container type in one place and have all your code reflect the changes. This is the C++ way to abstract data types (whereas eg. in C# you'd have a property returning IEnumerable<Wheel>).

Upvotes: 34

Rohit Vipin Mathews
Rohit Vipin Mathews

Reputation: 11787

typedef int mark;  // for in built data types

class abc
{
};

typedef abc XYZ; // for user written classes.

Typedef allows you to alias a class or datatype name with a more context sensitive name corresponding to the scenario.

Upvotes: 1

ApprenticeHacker
ApprenticeHacker

Reputation: 22031

You can use the typedef keyword:

typedef LONGNAME LN;

You can also do something like:

typedef class {

...

} LN;

Edit: You may run into trouble when using templates though. See here for a possible solution.

Upvotes: 6

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