How to define a common type limit for primitive types?

Question

I have the following method with a generic type:

T GetValue<T>(); 

I would like to restrict T to primitive types such as int, string, float, but not class type. I know that I can define generic for a class type as follows:

 C GetObject<C>() where C: class; 

I'm not sure if this is possible for primitive types and how to do it.

Answer 1

You can use this to restrict it to type values:

 where C: struct 

You also specify a string. Unfortunately, strings will not be allowed, as they are not value types.

Answer 2

This actually does the job to a certain extent:

 public T Object<T>() where T : struct, IComparable, IFormattable, IConvertible, IComparable<T>, IEquatable<T> 

To limit the number types, you can get helpful hints for the following patterns defined for the ValueType class

Answer 3

which you are looking for:

 T GetObject<T> where T: struct; 

Answer 4

There is no general restriction that would fit this set of things cleanly. What do you really want to do? For example, you can crack it with runtime checks like static ctor (for generic types - not so easy for generic methods) ...

However; more often than not, I see this because people want one of:

• to be able to check elements for equality: in this case use EqualityComparer<T>.Default
• to be able to compare / sort items: in this case use Comparer<T>.Default
• to be able to do arithmetic: in this case use MiscUtil support for common operators

Answer 5

What are you really trying to do in a method? Perhaps you really need C to implement IComparable or another interface. In this case, you need something like

 T GetObject<T> where T: IComparable