RFR: 8369564: Provide a MemorySegment API to read strings with known lengths [v7]

[Maurizio Cimadamore]

On Wed, 19 Nov 2025 20:34:21 GMT, ExE Boss <duke at openjdk.org> wrote:

>> src/java.base/share/classes/java/lang/String.java line 2019:
>> 
>>> 2017:     }
>>> 2018: 
>>> 2019:     boolean bytesCompatible(Charset charset, int srcIndex, int numChars) {
>> 
>> Surprisingly here we don't do anything for the case where the string is UTF16 and the target charset is also UTF16?
>
> The **UTF‑16** `Charset`s disallow unpaired surrogates, which **Java** `String`s allow.
> 
> So this can only return `true` for **UTF‑16** when the platform and charset endianness match and the `String` doesn’t have any unpaired surrogates.

Yeah, tricky stuff -- we'll need to think more before changing this

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PR Review Comment: https://git.openjdk.org/jdk/pull/28043#discussion_r2545655612