Surrogates and noncharacters

[Hans Aberg]

> On 10 May 2015, at 12:23, Richard Wordingham <richard.wordingham at ntlworld.com> wrote:

>> However I wonder what would be the effect of D80 in UTF-32: is
>> <0xFFFFFFFF> a valid "32-bit string" ?
> 
> The value 0xFFFFFFFF cannot appear in a UTF-32 string.  Therefore it
> cannot represent a unit of encoded text in a UTF-32 string.

Even though the values with highest bit set are not a part of original UTF-32, it can easily be extended also to original UTF-8, which may be simpler to implement.