Re: Using emplace leading to memory corruption

[lomereiter]

You didn't tell GC that the allocated memory contains pointers to 
GC'd data.
Therefore, it thinks that the class members can be freed, which 
is not the case.

Adding lines
import core.memory; GC.addRange(tmp, size);
resolves the problem. You must also call GC.removeRange(tmp) when 
you will free the allocated memory.

      void[] mem = tmp[0..size];                           // 39
      _foo = emplace!(Foo)(mem);                           // 40