Function read_con_string_iterator 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn read_con_string_iterator(
    contents_c: *const c_char,
) -> *mut CConFrameIterator

Iterate frames from an in-memory CON text buffer (null-terminated C string).

Use when the caller already decompressed (chemfiles, custom I/O) and wants to avoid a temp file. Same ownership rules as read_con_file_iterator.

Safety

contents_c must be a valid null-terminated UTF-8 string, or NULL (returns NULL).