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?