#1,035 – Summary of Type Parameter Constraints

Here’s a quick summary of the different types of constraints that you can apply to type parameters:

• Require parameter’s type to derive from a specified class: where T : [base-class]
• Require parameter’s type to implement an interface: where T : [interface]
• Require parameter’s type to be reference type: where T : class
• Require parameter’s type to be value type: where T : struct
• Require parameter’s type to implement parameterless constructor: where T : new()
• Require parameter’s type to derive from another type parameter: where T : U