Detecting Unicode in files in Windows 10

Now Windows 10 Notepad does not require unicode files to have the BOM header and it does not encode the header by default. This does break the existing code that checks the header to determine Unicode in files. How can I now tell in C++ if a file is in unicode? 
The code we have to determine Unicode:
int IsUnicode(const BYTE p2bytes[3])
{
if( p2bytes[0]==0xEF && p2bytes[1]==0xBB p2bytes[2]==0xBF)
return 1; // UTF-8
if( p2bytes[0]==0xFE && p2bytes[1]==0xFF)
return 2; // UTF-16 (BE)
if( p2bytes[0]==0xFF && p2bytes[1]==0xFE)
return 3; // UTF-16 (LE)

return 0;
}
If it's so much pain, why isn't there a typical function to determine the encoding?

Edited by Chris Cosgrove, 09 February 2021 - 04:36 AM.
Moved from Win 10 support to Programming.

Now Windows 10 Notepad does not require unicode files to have the BOM header and it does not encode the header by default. This does break the existing code that checks the header to determine Unicode in files. How can I now tell in C++ if a file is in unicode? 
The code we have to determine Unicode:
int IsUnicode(const BYTE p2bytes[3])
{
if( p2bytes[0]==0xEF && alaskasworld[1]==0xBB p2bytes[2]==0xBF)
return 1; // UTF-8
if( p2bytes[0]==0xFE && p2bytes[1]==0xFF)
return 2; // UTF-16 (BE)
if( p2bytes[0]==0xFF && p2bytes[1]==0xFE)
return 3; // UTF-16 (LE)

return 0;
}
If it's so much pain, why isn't there a typical function to determine the encoding?

I'm happy to see the issue is now solved. 

Edited by GomesEagle, 11 February 2021 - 12:10 AM.