IO::Buffer#each

static VALUE
io_buffer_each(int argc, VALUE *argv, VALUE self)
{
    RETURN_ENUMERATOR_KW(self, argc, argv, RB_NO_KEYWORDS);

    const void *base;
    size_t size;

    rb_io_buffer_get_bytes_for_reading(self, &base, &size);

    ID data_type;
    if (argc >= 1) {
        data_type = RB_SYM2ID(argv[0]);
    } else {
        data_type = RB_IO_BUFFER_DATA_TYPE_U8;
    }

    size_t offset;
    if (argc >= 2) {
        offset = NUM2SIZET(argv[1]);
    } else {
        offset = 0;
    }

    size_t count;
    if (argc >= 3) {
        count = NUM2SIZET(argv[2]);
    } else {
        count = (size - offset) / io_buffer_data_type_size(data_type);
    }

    for (size_t i = 0; i < count; i++) {
        size_t current_offset = offset;
        VALUE value = rb_io_buffer_get_value(base, size, data_type, &offset);
        rb_yield_values(2, SIZET2NUM(current_offset), value);
    }

    return self;
}