Optional and NotNull version 0.5.0 - swift optional like and scala option like

[Petar]

On Thursday, 16 August 2018 at 18:10:38 UTC, jmh530 wrote:
> On Thursday, 16 August 2018 at 12:25:14 UTC, aliak wrote:
>> Hi
>>
>> See: https://optional.dub.pm
>>
>> I've totally revamped the Optional type and am now quite happy 
>> with. It has a range interface and safe dispatching and can be 
>> used to 1) avoid null dereferencing, 2) have non-null 
>> guarantees, and 3) show clear intent where there may or may 
>> not be a value. It's also @nogc and @safe and mutation of the 
>> original object during safe dispatching works as well.
>>
>
> The readme.md page looks great. You might mention that it works 
> with @nogc and @safe (I presume Optional and NotNull).
>
> One question: Suppose there was a @weaksafe that has all the 
> same features @safe except that it relaxed the requirement of 
> "No taking the address of a local variable or function 
> parameter." so that you could take the address of a NotNull 
> variable. Are there any reasons why this would be unsafe? I 
> imagine NotNull requires some type of run-time checking, but 
> other than that I don't see why not.

Actually "@weaksafe" already exists in the form of `@safe` + 
`-dip1000` - you can take the address of a local variable in 
`@safe` code and then you get a `scope`-ed pointer, which you're 
not allowed to escape.