import std.experimental.allocator.building_blocks.null_allocator : NullAllocator; import std.experimental.allocator.mallocator : Mallocator; import std.experimental.allocator.gc_allocator : GCAllocator; import std.experimental.allocator.mmap_allocator : MmapAllocator; struct S { mixin AllocatorState!NullAllocator n; mixin AllocatorState!GCAllocator g; mixin AllocatorState!Mallocator m; mixin AllocatorState!MmapAllocator p; } static assert(S.sizeof == 1);
State of an allocator A.
AllocatorState!(A).sizeof is zero for A being NullAllocator, Mallocator, GCAllocator, and MMapAllocator and typically non-zero for the other.