Is using the new System.Tuple class bad design?

Question

I like the concept of System.Tuple in that it allows me to return multiple parameters in a single function call without instantiating a new class, however does this defy any good programming practices such as Microsoft Patterns & Practices, SOLID Principles, etc.

I'm just trying to gauge how liberally I should use this feature or if I should only use it in edge case scenarios when necessary.

Answer 1

The issue with using Tuple is that the generic type parameters do not convey meaning.

For readability you may want to consider using a custom class or even an anonymous type with named members.

Answer 2

One of the most important code qualities is readability. So ask yourself:
When I (i.e. in anybody else but you) look at the method signature, do I know what meaning the respective components of the Tuple have?
For example if the pair of floats you are returning is a set of polar coordinates, is this clear?

This is clear:

Tuple<Float, Float> getPolarCoords();

This is misleading (because one would assume Cartesian coordinates):

Tuple<Float, Float> getCoords();

And this is devoid meaning:

Tuple<Float, Float> getTuple();

So generally speaking, you will have evaluate clarity on a per-case basis and refactor if necessary. If you represent the same kind of data as Tuple in many different places, then creating a class is definitely a good idea.