Why does this implicit conversion from int to uint work?

Question

Using Casting null doesn't compile as inspiration, and from Eric Lippert\'s comment:

That demonstrates an interesting case. \"uint x = (int)0;\" w

Answer 1

Integer constant conversions are treated as very special by the C# language; here's section 6.1.9 of the specification:

A constant expression of type int can be converted to type sbyte, byte, short, ushort, uint, or ulong, provided the value of the constant-expression is within the range of the destination type. A constant expression of type long can be converted to type ulong, provided the value of the constant expression is not negative.

This permits you to do things like:

byte x = 64;

which would otherwise require an ugly explicit conversion:

byte x = (byte)64; // gross