Static import in C++11 (e.g. an enum class)

Question

My usage of enum class (VS2012):

class matrix {
public:
    enum class operation_type {ADD, MULT};
    matrix(operation_type op);
...
}

and in another fragment I use

matrix* m = new matrix(matrix::operation_type::ADD);

If the names are long, this becomes very messy.

Is it possible to somehow import the enum values so that I could write:

matrix* m = new matrix(ADD);

The same regards nested classes - can I import them?

score 5 · Accepted Answer · answered Mar 16 '13 at 13:54

5

No, it is not possible.

You cannot omit the operation_type part, because you have made this a scoped enumeration (and that is what scoped enumeration are all about). If you want to avoid it, you have to make it an unscoped enum (removing the class keyword).

Besides, outside of matrix you cannot import a member name through a using declaration as if matrix was a namespace. Moreover, per Paragraph 7.3.3/7 of the C++11 Standard:

A using-declaration shall not name a scoped enumerator.

answered Mar 16 '13 at 13:54

Andy Prowl

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you mean if I have `class A {public: class B {} }` then I can't write `using A::B`, right? – Joshua MN Mar 16 '13 at 14:18
@JoshuaMN: I believe you can only do that if you write it inside a subclass of `A`. – Andy Prowl Mar 16 '13 at 14:21

Static import in C++11 (e.g. an enum class)

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