Why is D's GC slower than GO's?

[Walter Bright]

On 10/29/2022 1:11 PM, Paulo Pinto wrote:
> Again mixing languages,
> 
> __gc is from Managed C++, .NET 1.0
> 
> C++/CLI, .NET 2.0 onwards, uses ^ for reference types and gcnew for GC heap.

What's the difference between __gc* and ^ ?