Compiler Error CS0283

The type 'type' cannot be declared const

The type specified in a constant declaration must be byte, sbyte, ushort, short, uint, int, ulong, long, char, float, double, decimal, bool, string, an enum type, or a reference type that is assigned a value of null. Each constant expression must yield a value of the target type or of a type that is implicitly convertible to the target type.

Example

The following example generates CS0283.

C#

// CS0283.cs  
struct MyTest  
{  
}  
class MyClass
{  
    // To resolve the error but retain the "const-ness",  
    // change const to readonly.  
    const MyTest test = new MyTest();   // CS0283  
  
    public static int Main() {  
        return 1;  
    }  
}