Manually calling postblots recursively

[Johannes Loher via Digitalmars-d-learn]

Hey, I'm trying to work on 
https://issues.dlang.org/show_bug.cgi?id=15708 so I decided it 
might be interesting to find a way to (recursively) call all 
postblits that belong to certain struct or static array. This is 
what I came up with so far:

import std.traits;

void callPostblits(S)(ref S s)
{
     static if (isStaticArray!S && S.length)
     {
         foreach (ref elem; s)
             callPostblits(elem);
     }
     else static if (is(S == struct))
     {
         foreach (field; FieldNameTuple!S)
         {
             callPostblits(__traits(getMember, s, field));
         }

         static if (hasMember!(S, "__postblit"))
         {
             s.__postblit();
         }
     }
}

@safe unittest
{

     struct AnotherTestStruct
     {
         int b = 0;

         this(this)
         {
             b = 1;
         }
     }

     struct TestStruct
     {
         int a = 0;

         this(this)
         {
             a = 1;
         }

         AnotherTestStruct anotherTestStruct;
     }


     TestStruct[2] testStructs;

     assert(testStructs[0].a == 0 && 
testStructs[0].anotherTestStruct.b == 0);
     assert(testStructs[1].a == 0 && 
testStructs[1].anotherTestStruct.b == 0);

     callPostblits(testStructs);

     assert(testStructs[0].a == 1 && 
testStructs[0].anotherTestStruct.b == 1);
     assert(testStructs[1].a == 1 && 
testStructs[1].anotherTestStruct.b == 1);
}

Any suggestions for improvement or cases where this fails?