Function r_core::r_print_format

pub unsafe extern "C" fn r_print_format(
    p: *mut RPrint, 
    seek: c_ulonglong, 
    buf: *const c_uchar, 
    len: c_int, 
    fmt: *const c_char, 
    elem: c_int, 
    setval: *const c_char, 
    field: *mut c_char
) -> c_int