utf16 (source -- result)

Converts one accepted UTF-8 source into one zero-terminated Nat16 Array containing the UTF-16 representation.

• Accepted source forms are StringView, Text, and String.
• These inputs are normalized through String.makeStringView before conversion begins.
• The whole source is interpreted as UTF-8 and converted to UTF-16 code units.
• Unicode code points outside the Basic Multilingual Plane are represented by ordinary UTF-16 surrogate pairs.
• The resulting Nat16 Array always ends with one trailing 0n16 terminator.
• The returned array owns its storage and is independent of the source lifetime.
• The result remains dynamic even when the source is known at compile time.
• The resulting array can be passed through storageAddress to imported Windows functions that expect zero-terminated UTF-16 input.

Failure conditions

• Invalid UTF-8 input causes assertion failure.
• An empty source causes assertion failure.
• Unexpected conversion failure likewise causes assertion failure.
• These failure paths use the assertion text MultiByteToWideChar failed.

See also

• String: UTF-8 string views, owned strings, formatting helpers, and text conversion utilities.
• Array: Growable array.
• windows/kernel32: Kernel32 declarations for synchronization, process, thread, file, and timing helpers.