How long does the context of a delegate exist?

[Steven Schveighoffer]

On 5/27/21 4:46 PM, IGotD- wrote:
> On Thursday, 27 May 2021 at 18:13:17 UTC, Adam D. Ruppe wrote:
>>
>> If the delegate is created by the GC and stored it will still be 
>> managed by the GC, along with its captured vars.
>>
>> As long as the GC can see the delegate in your example you should be 
>> OK. But if it is held on to by a C or OS lib, the GC might not see it 
>> and you'd have to addRoot or something to ensure it stays in.
> 
> With lambdas in C++ you can cherrypick captures the way you want, then 
> somehow this can be converted to an std::function and this is where it 
> goes on the heap as well.
> 
> In D, how does the compiler know what captures it is supposed to store, 
> or does it take the whole lot?

For closures, it uses semantic analysis to see which variables are used 
in the lambda, and then allocates a block at the start of the function 
to hold those variables.

-Steve