import std.stdio;
 
struct Foo
{
    int[] a;
    int b;
    this(this)
    {
        writeln("blit copy is done now let's post-blit'");
        // a memory is the same as the source
        a = a.dup;
        // a memory is now only for this instance
    }
}
 
void main()
{
    Foo foo1 = Foo([1,2], 3);
    writeln("blit copy will happen");
    Foo foo2 = foo1;
    // would be true without the "postblit"
    assert(foo1.a.ptr != foo2.a.ptr);
}

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