UTF-8 string conversion methods about jni-bind

[jwhpryor]

Ok, you're specifically referring to UTF8 correct?

If so, could you update the bug title to reflect that? I assume you're aware that there are already string conversions for existing char*, std::string etc.

[jwhpryor]

So, I took a pass through your conversion code, and had a chance to think a bit on this myself.

I think your conversion may be simple a subset of the behaviour LocalString already supports.

The former case is a function that takes in a std::string and performs a conversion to UTF16 from UTF8. I believe just using a regular ctor is equivalent?

The latter converts from a UTF16 string to a regular std::string, however, LocalString just directly asks for a UTF8 string, so you're probably just making your conversion explicit, or making an unnecessary one (I don't know what the JVM does internally).

That said, in C++20, UTF16 has its own view std::filesystem::path::u16string. Here, calling GetUtfString could actually be efficiently represented. So, I think this should be revisited when C++20 support is added, but I think your conversion methods are already covered.