Why Do Explicit Type Arguments Work with Non-Generic Methods or Constructors?

Why does giving explicit type arguments to a non-generic method or constructor compile?

In languages like C#, it is possible to specify type arguments when calling non-generic methods or creating instances of non-generic constructors. This behavior can be confusing, as one might expect a compile-time error when doing so because non-generic methods are not defined with type parameters.

public class Example {
    public void Print(string message) {
        Console.WriteLine(message);
    }
}

// Calling a non-generic method with explicit type arguments
var example = new Example();
example.Print<string>("Hello, World!"); // Compiles, but string is unnecessary.

Causes

• The language allows for explicit type parameters for the purposes of consistency in method calls, even if the method itself is not generic.
• This can be useful in scenarios like method overloading, where developers might want to maintain a common calling syntax across both generic and non-generic methods.

Solutions

• Understand that while the explicit type arguments can appear in method calls, they have no effect on method behavior and are simply ignored by the compiler.
• To ensure code clarity, avoid using explicit type arguments with non-generic methods unless necessary for consistency.

Mistake: Assuming that providing type arguments to a non-generic method changes its behavior.

Solution: Remember that type arguments in this context are ignored; they do not influence the method signature.

Mistake: Using explicit type arguments out of habit or for consistency when they are not needed.

Solution: Only use type arguments when invoking generic methods for clarity and maintainability.