How to Resolve Error "CS0522: structs cannot call base class constructors" in C#

The Compiler Error CS0522 is a syntax restriction related to Value Types. The message reads: "Structs cannot call base class constructors".

In C#, a struct is a value type. While all structs implicitly inherit from System.ValueType (which in turn inherits from System.Object), C# does not support user-defined inheritance for structs. You cannot define a struct that inherits from a class or another struct. Because there is no "parent class" logic that you are allowed to invoke or modify, the compiler forbids the use of the : base(...) syntax in struct constructors.

This guide explains the limitations of struct inheritance and how to correctly initialize them.

Understanding Struct Inheritance

Classes support inheritance: class Child : Parent. When constructing a Child, you often need to ensure Parent is initialized, so you call base().

Structs are different:

• They are sealed. You cannot inherit from them.
• They cannot inherit from other types (except interfaces).
• Their inheritance from System.ValueType is handled implicitly and automatically by the runtime.

Since you cannot define a base class for your struct, calling base() is trying to call a constructor that is logically inaccessible to you.

Scenario: The Invalid Constructor Chain

This error often occurs when developers apply habits from Class-based Object Oriented Programming to Structs, assuming they need to call the object constructor.

Example of error:

public struct Point
{
    public int X;
    public int Y;

    // ⛔️ Error CS0522: structs cannot call base class constructors.
    // Even though Point technically inherits from System.ValueType -> System.Object,
    // C# forbids explicit calls to base() for structs.
    public Point(int x, int y) : base()
    {
        X = x;
        Y = y;
    }
}

Solution: Remove the Base Call

To fix this, simply remove the : base() part. Structs are initialized to zero/null by default before the constructor body runs; there is no parent initialization logic required.

Solution:

public struct Point
{
    public int X;
    public int Y;

    // ✅ Correct: No call to base().
    // You can still call other constructors in the SAME struct using 'this()'.
    public Point(int x, int y)
    {
        X = x;
        Y = y;
    }
}

note

Constructor Chaining (this): While base() is forbidden, chaining to other constructors within the same struct using : this(...) is perfectly valid and useful for setting default values.

Conclusion

CS0522 reminds you that Structs are not Classes.

1. No Inheritance: Structs do not participate in class hierarchies.
2. No Base: There is no base constructor for you to invoke.
3. The Fix: Delete : base() from your struct constructor declaration.