Question

I’m using a library that has classes with a number of enums. Here’s an example

class TGNumberFormat
{
  public:
  // ...
  enum EAttribute {   kNEAAnyNumber
    kNEANonNegative
    kNEAPositive
  };
  enum ELimit {   kNELNoLimits
    kNELLimitMin
    kNELLimitMax
    kNELLimitMinMax
  };
  enum EStepSize {   kNSSSmall
    kNSSMedium
    kNSSLarge
    kNSSHuge
  };
  // etc...
};

In the code I have to refer to these as TGNumberFormat::kNEAAnyNumber for example. I’m writing a GUI that uses these values very often and the code is getting ugly. Is there some way I can import these enums and just type kNEAAnyNumber? I don’t really expect any of these names to overlap. I’ve tried various ways of using the using keyword and none will compile.

Answer 1

If you are using these constants all over in your code, it might be beneficial to create your own header that redefines the values in a namespace. You can then using that namespace. You don’t need to redefine all of the values, just the names of the enumerators. For example,

namespace TGEnumerators
{
    static EAttribute const kNEAAnyNumber(TGNumberFormat::kNEAAnyNumber);
    // etc.
}

Alternatively, you can typedef TGNumberFormat to a shorter name in the functions or source files where you use it frequently. For example,

typedef TGNumberFormat NF;
NF::EAttribute attribute = NF::kNEAAnyNumber;

I’d argue that the latter approach is superior, and if used judiciously at block scope, is a fine practice. However, for use across a file, I think it’d be preferable to use the full names of the enumerators, for clarity.