Compiler Error CS0557

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Duplicate user-defined conversion in type 'class'

Duplicate conversion routines are not allowed in a class.

The following example generates CS0557:

// CS0557.cs
namespace x
{
    public class ii
    {
        public class iii
        {
        public static implicit operator int(iii aa)
        {
            return 0;
        }

    // CS0557, delete duplicate
        public static explicit operator int(iii aa)
        {
            return 0;
        }
        }

        public static void Main()
        {
        }
    }
}