Should a type for working with fractions be a class or a struct?

[kender_a]

Folks,

I’m making a C# type for working with fractions, and trying to follow best practices. My question is: should a type like this be a class (reference type) or a struct (value type)?

Here’s what I’m thinking.

• Fraction is a kind of a number, which makes me think that it should be a value type, and therefore a struct.
• System.Numerics.Complex has some similarities with a fraction type. Both represent a kind of a number. Both are small with only 2 numeric fields. System.Numerics.Complex is a stuct.

At the same time, I’ve found a couple of existing articles on CodeProject, which describe Fraction types. Both of them are classes.

Fraction class in C# [Syed Mehroz Alam, CodeProject, 2005]
Fractions in C# [Nikola Stepan, CodeProject, 2005]

The authors don’t explain why they chose to declare classes rather than structs. Something like that makes me think that there may be something that I don’t understand that was fairly obvious to them.

Any suggestion, insight or reference is really appreciated!

Cheers,
- Nick

P.S. For the most part, I work mostly with C and C++, where I have fine control over things like const, pointers, references. Of course, that comes at a risk of having nasty pointer-related bugs.