Compiler Error CS1959

'name' is of type 'type'. The type specified in a constant declaration must be sbyte, byte, short, ushort, int, uint, long, ulong, char, float, double, decimal, bool, string, an enum-type, or a reference-type.

The types permitted in a const declaration are limited to those described in this message.

To correct this error

  1. Declare the constant with an allowed type.


The following code produces CS1959 because null is not a type.

// cs1959.cs  
class Program  
        static void Test<T>() where T : class  
            const T x = null; // CS1959  

See also