Make AffixAllocator take into account RCISharedAllocator

Author: edi33416

std/experimental/allocator/building_blocks/affix_allocator.d

@@ -24,7 +24,8 @@ struct AffixAllocator(Allocator, Prefix, Suffix = void)
 {
     import std.algorithm.comparison : min;
     import std.conv : emplace;
-    import std.experimental.allocator : RCIAllocator, theAllocator;
+    import std.experimental.allocator : RCIAllocator, RCISharedAllocator,
+           theAllocator, processAllocator;
     import std.experimental.allocator.common : stateSize, forwardToMember,
         roundUpToMultipleOf, alignedAt, alignDownTo, roundUpToMultipleOf,
         hasStaticallyKnownAlignment;
@@ -69,11 +70,21 @@ struct AffixAllocator(Allocator, Prefix, Suffix = void)
     static if (stateSize!Allocator)
     {
         Allocator _parent;
-        static if (is(Allocator == RCIAllocator))
+        static if (is(Allocator == RCIAllocator) || is(Allocator == RCISharedAllocator))
         {
             Allocator parent()
             {
-                if (_parent.isNull) _parent = theAllocator;
+                if (_parent.isNull)
+                {
+                    static if (is(Allocator == RCIAllocator))
+                    {
+                        _parent = theAllocator;
+                    }
+                    else
+                    {
+                        _parent = processAllocator;
+                    }
+                }
                 assert(alignment <= _parent.alignment);
                 return _parent;
             }
@@ -499,3 +510,12 @@ struct AffixAllocator(Allocator, Prefix, Suffix = void)
     assert(b.length == 100);
     assert((() nothrow @nogc => a.deallocate(b))());
 }
+
+@system unittest
+{
+    import std.experimental.allocator : RCISharedAllocator, processAllocator;
+
+    AffixAllocator!(RCISharedAllocator, uint) a;
+    auto buf = a.allocate(42);
+    assert(buf.length == 42);
+}