Reading this, I learned it was possible to allow a method to accept parameters of multiple types by making it a generic method. In the example, the following code is used with a type constraint to ensure "U" is an IEnumerable<T>
.
public T DoSomething<U, T>(U arg) where U : IEnumerable<T> { return arg.First(); }
I found some more code which allowed adding multiple type constraints, such as:
public void test<T>(string a, T arg) where T: ParentClass, ChildClass { //do something }
However, this code appears to enforce that arg
must be both a type of ParentClass
and ChildClass
. What I want to do is say that arg could be a type of ParentClass
or ChildClass
in the following manner:
public void test<T>(string a, T arg) where T: string OR Exception { //do something }
Your help is appreciated as always!
Multiple interface constraints can be specified. The constraining interface can also be generic. In a nullable context in C# 8.0 and later, T must be a non-nullable type that implements the specified interface.
C# allows you to use constraints to restrict client code to specify certain types while instantiating generic types. It will give a compile-time error if you try to instantiate a generic type using a type that is not allowed by the specified constraints.
A Generic class can have muliple type parameters.
Interface Type Constraint You can constrain the generic type by interface, thereby allowing only classes that implement that interface or classes that inherit from classes that implement the interface as the type parameter.
That is not possible. You can, however, define overloads for specific types:
public void test(string a, string arg); public void test(string a, Exception arg);
If those are part of a generic class, they will be preferred over the generic version of the method.
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