Xapian discuss - Sep 2008 - Semantics of terms - do they have to be C style, '\0' terminated strings?

Briefly: my goal is to index a series of 64 bit numeric values with every
document.

I see that WritableDocument::add_term takes a C++ string argument.
I believe that C++ strings allow bytes with a value of 0x0 (or '\0'),
however I'm pretty
sure that all is lost if you then call string.c_str().

Is it defined anywhere whether the string you pass to add_term has to be "C
style" or not?

At a glance the code base doesn't call c_str() much and the cases I saw had
to do with filenames, so this might be OK,
I just wanted to check if this was, say, guaranteed by the contract or if
this is just too dubious.

thx
 Dave

On Wed, Sep 10, 2008 at 11:21:53PM -0700, David Spencer
wrote:
> Is it defined anywhere whether the string you pass to add_term has to be
"C
> style" or not?
All handling of "data" strings in the C++ API is zero-byte clean.

The C# and Java bindings aren't currently though.

And the quartz and flint backends internally do some messing around with
zero bytes in terms, which essentially means that each zero byte in a
term counts twice towards the term length limit at the moment.  But the
limit is a bit over 240, so that's rarely an issue.
> At a glance the code base doesn't call c_str() much and the cases I saw
had
> to do with filenames, so this might be OK,
Yes, filenames can't contain zero bytes, and OS/library calls take
nul-terminated strings as const char * (or similar), so calling c_str()
in such cases isn't a problem.

Cheers,
    Olly