Re: Deprecating --enable-bounds-check?

[John W. Eaton]

On 05/11/2017 04:17 PM, Rik wrote:

> What is the 2x2 decision diagram for this?
>
>           const    non-const
>         |        |           |
>  unique |        |           |
>         |--------|-----------|
>  same   |        |           |
>         |        |           |

For a const object there is never a difference.  It can't be modified so 
the indexing operator doesn't need to check the reference count or make 
the representation unique.

For non-const, there is always a check of the reference count.  If the 
reference count is greater than 1, then there is a copy on the first 
call to the indexing operator.

jwe