DIP1000: Scoped Pointers (Discussion)

[John Colvin via Digitalmars-d]

On Thursday, 11 August 2016 at 08:45:38 UTC, Walter Bright wrote:
> On 8/11/2016 1:29 AM, John Colvin wrote:
>> Can someone talk me through the lifetime algebra for the 
>> following?
>>
>> void foo()
>> {
>>     int a;
>>     int** c;
>>     void bar()
>>     {
>>         int* b = &a;  <= ok, b has a smaller lifetime than a
>>         c = &b;    <= error, c has a larger lifetime than b
>>     }
>>     bar();
>>     *c; //undefined behaviour
>> }

but according to this rule:

"For an unrestricted pointer, visibility is dictated by the usual 
lexical scope rules. Lifetime, however is dictated by the 
lifetime of the data to which the pointer points to."

b should have the same lifetime as a, no?