// Originally compiled with dmd 2.031 on Gentoo Linux.
import std.stdio;

class Foo
{
    Foo b;
    int c;
    Foo d;
    int e;
    int q;

    Foo f;

    Foo opIndex( int val )
    {
        writefln("Foo[%d]",val);
        if ( f is null )
            f = new Foo();
        return f;
    }

    Foo opIndexAssign( Foo foo, int val )
    {
        writefln("Foo[%d] = foo",val);
        return f = foo;
    }
}

void main()
{
    Foo a = new Foo();
    a.b = new Foo();
    a.d = new Foo();
    Foo p = new Foo();

    void reset()
    {
        a.b.e = 42;
        a.b.c = 10;
        a.d.c = 8;
        p.q = 4;
    }

    void printAll()
    {
        writefln("a.b.c = %d", a.b.c);
        writefln("a.b.e = %d", a.b.e);
        writefln("a.d.c = %d", a.d.c);
        writefln("p.q   = %d", p.q);
    }

    reset();
    writefln("initial state:");
    printAll();

    writefln("");
    writefln("monstrosity 1 results:");
    a.d[a.b.c++].c *= (p.q++) * (a.b.e = 3);
    printAll();

    reset();
    writefln("");
    writefln("monstrosity 2 results:");
    auto t1 = a;
    auto t2 = t1.d;   // a.d[...]
    auto t3 = t1.b;   // a.b.c++
    auto t4 = t3.c;   // a.b.c++
    auto t5 = t2[t4]; // a.d[a.b.c++]
    auto t6 = t5.c;   // a.d[a.b.c++].c

    // (p.q++)
    auto t7 = p;
    auto t8 = t7.q;

    // (a.b.e = 3)
    auto t9 = a; // Must be done again since it appears twice in the expression.
    auto t10 = t9.b;

    // Do not make a new temporary for .c;
    // Explicit assignments call only write properties.  They do not read.
    t6 *= t8 * (t10.e = 3);

    // (a.b.e = 3)
    // t9.b = t10; // Multiple assignments to b are refused. Already done at bottom.
    // a = t9; // Multiple assignments to a are refused.  Already done at bottom.

    // a.d[a.b.c++].c = ...
    t5.c = t6;

    // a.d[...]
    t2[t4] = t5;
    t1.d = t2;
    // a = t1; // Multiple assignments to a are refused.  Already done at bottom.

    // The opPostInc expressions must be done last.
    // (p.q++)
    t8++;
    t7.q = t8;
    p = t7;

    // (a.b.c++)
    t4++;
    t3.c = t4;
    t1.b = t3;
    a = t1;

    // END
    printAll();
}

/* This program should print the following:
initial state:
a.b.c = 10
a.b.e = 42
a.d.c = 8
p.q   = 4

monstrosity 1 results:
Foo[10]
a.b.c = 11
a.b.e = 3
a.d.c = 8
p.q   = 5

monstrosity 2 results:
Foo[10]
Foo[10] = foo
a.b.c = 11
a.b.e = 3
a.d.c = 8
p.q   = 5
*/