S3453 — Classes should not have only "private" constructors

Why is this an issue?

When a class has only a private constructor, it can’t be instantiated except within the class itself. Such classes can be considered dead code and should be fixed

Exceptions

• Classes that access their private constructors (singletons or smart enums) are ignored.
• Classes containing only static members, nested types, or both are ignored. Classes with only static members are covered by Rule S1118.
• Classes that derive from SafeHandle since they can be instantiate through P/Invoke.

How to fix it

Code examples

Noncompliant code example

Public Class [MyClass] ' Noncompliant: the class contains only private constructors
    Private Sub New()
        ' ...
    End Sub
End Class

Compliant solution

Public Class [MyClass] ' Compliant: the class contains at least one non-private constructor
    Public Sub New()
        ' ...
    End Sub
End Class

Resources

Documentation

• S1118 - Utility classes should not have public constructors
• Microsoft Learn - SafeHandle Class
• Microsoft Learn - Platform Invoke (P/Invoke)
• Microsoft Learn - Use enumeration classes instead of enum types
• Wikipedia - Dead code
• Wikipedia - Singleton pattern