Function pio_convert_str 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn pio_convert_str(
    text: *const c_char,
    from: *const c_char,
    to: *const c_char,
    warnbuf: *mut c_char,
    warnlen: usize,
    errbuf: *mut c_char,
    errlen: usize,
) -> *mut c_char

Convert in-memory case text from format from (required; there is no path to infer from) to format to, without keeping a handle: the in-memory sibling of pio_convert_file. Returns the converted text as an owned C string (free with pio_string_free), NULL on error. Fidelity warnings, read side first, are written \n-joined into warnbuf.