import std.stdio;

​

mixin template S1andS2Fields()

{    

    int field1;

    string field2;    

}

​

struct S1

{

    mixin S1andS2Fields;

}

​

struct S2

{

    mixin S1andS2Fields;

}

​

struct S3

{

    S2 s;

    alias s this;

}

​

void main(string[] args)

{

    S1 s1;

    S2 s2;

    S2 s3;

    s1.field1 = 1;

    s1.field2 = "Hello S1";

    s2.field1 = 2;

    s2.field2 = "Hello S2";

    s3.field1 = 3;

    s3.field2 = "Hello S3";

    writeln(s1.field1);

    writeln(s1.field2);

    writeln(s2.field1);

    writeln(s2.field2);

    writeln(s3.field1);

    writeln(s3.field2);

}