April 05, 2011
The following section from the Language Reference does not correspond to the current dmd compiler (v2.052, Windows) behaviour:

"
Integer values cannot be implicitly converted to another type that cannot
represent the integer bit pattern after integral promotion. For example:

ubyte  u1 = cast(byte)-1;   // error, -1 cannot be represented in a ubyte
ushort u2 = cast(short)-1;  // error, -1 cannot be represented in a ushort
uint   u3 = cast(int)-1;    // ok, -1 can be represented in a uint
ulong  u4 = cast(ulong)-1;  // ok, -1 can be represented in a ulong
"

Both byte and short casts work all right.
April 05, 2011
On Tue, 05 Apr 2011 20:10:19 +0200, Morlan <home@valentimex.com> wrote:

> The following section from the Language Reference does not correspond to
> the current dmd compiler (v2.052, Windows) behaviour:
>
> "
> Integer values cannot be implicitly converted to another type that cannot
> represent the integer bit pattern after integral promotion. For example:
>
> ubyte  u1 = cast(byte)-1;   // error, -1 cannot be represented in a ubyte
> ushort u2 = cast(short)-1;  // error, -1 cannot be represented in a ushort
> uint   u3 = cast(int)-1;    // ok, -1 can be represented in a uint
> ulong  u4 = cast(ulong)-1;  // ok, -1 can be represented in a ulong
> "
>
> Both byte and short casts work all right.

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-- 
Simen