+ docs in xo-alloc2/ + misc improvements

xo-alloc2/src/alloc2/AAllocator.cpp

@@ -0,0 +1,19 @@
+/** @file AAllocator.cpp **/
+
+#include "xo/alloc2/AAllocator.hpp"
+
+namespace xo {
+    using xo::facet::DVariantPlaceholder;
+    using xo::facet::typeseq;
+    using xo::facet::valid_facet_implementation;
+
+    namespace mm {
+        int32_t
+        IAllocator_Any::s_typeseq = typeseq::id<DVariantPlaceholder>;
+
+        bool
+        IAllocator_Any::_valid = valid_facet_implementation<AAllocator, IAllocator_Any>;
+    }
+}
+
+/* end AAlocator.cpp */