How to get nogc to work with manual memory allocation

[via Digitalmars-d-learn]

On Friday, 5 September 2014 at 06:43:56 UTC, monarch_dodra wrote:
> On Sunday, 24 August 2014 at 09:29:53 UTC, Jacob Carlborg wrote:
>> On 2014-08-24 10:03, Bienlein wrote:
>>
>>> I have omitted the code for the TestClass class to save 
>>> space. Problem
>>> is that the compiler outputs this:
>>>
>>> Error: @nogc function 'main.nogcNew!(TestClass, ).nogcNew' 
>>> cannot call
>>> non- at nogc function 'core.exception.onOutOfMemoryError'
>>> Error: @nogc function 'main.nogcNew!(TestClass, ).nogcNew' 
>>> cannot call
>>> non- at nogc function 'std.conv.emplace!(TestClass, ).emplace'
>>> Error: @nogc function 'main.nogcDel!(TestClass).nogcDel' 
>>> cannot call
>>> non- at nogc function 'object.destroy!(TestClass).destroy'
>>>
>>> Is there a way to get around this?
>>
>> @nogc is a very new attribute. The runtime and standard 
>> library have not been properly annotated with this attribute 
>> yet.
>>
>> As a workaround you could try copy implementation of these 
>> functions to you're own code and annotate them as appropriate.
>
> The real issue here is actually the *language*. Exceptions and 
> Errors are GC allocated, so if you try to "check" your no-GC 
> allocation, you'll use the GC...
>
> A possible workaround is to preemptively static allocate the 
> Error. However, this can cause issues if you chain Errors, or 
> re-enter your function while throwing.

It was also discussed to exempt `new Error` (and assert) from the 
@nogc restriction.