Index: main.d
==================================================================
--- main.d
+++ main.d
@@ -5,17 +5,17 @@
  * Entry point for Polemy interpreter.
  */
 
 import std.stdio;
 import polemy.eval;
+
+version(unittest) static ~this()
+{
+	writeln( "***********************" );
+	writeln( "* All Tests Passed <3 *" );
+	writeln( "*********************** (Press Enter to finish)" );
+	readln();
+}
 
 void main( string[] args )
 {
-	version(unittest)
-	{
-		writeln( "***********************" );
-		writeln( "* All Tests Passed <3 *" );
-		writeln( "*********************** (Press Enter to finish)" );
-		readln();
-		return;
-	}
 }

Index: polemy/ast.d
==================================================================
--- polemy/ast.d
+++ polemy/ast.d
@@ -19,67 +19,67 @@
 class DeclStatement : Statement
 {
 	string     var;
 	Expression expr;
 	mixin SimpleConstructor;
-	mixin SimpleCompare; // do not take "pos" into account
+	mixin SimpleCompare;
 }
 
 class ExprStatement : Statement
 {
 	Expression expr;
 	mixin SimpleConstructor;
-	mixin SimpleCompare; // do not take "pos" into account
+	mixin SimpleCompare;
 }
 
 abstract class Expression
 {
 	immutable LexPosition pos;
 	mixin SimpleConstructor;
-	mixin SimpleCompare; // do not take "pos" into account
+	mixin SimpleCompare;
 }
 
 class StrLiteralExpression : Expression
 {
 	string data;
 	mixin SimpleConstructor;
-	mixin SimpleCompare; // do not take "pos" into account
+	mixin SimpleCompare;
 }
 
 class IntLiteralExpression : Expression
 {
 	BigInt data;
 	mixin SimpleConstructor;
-	mixin SimpleCompare; // do not take "pos" into account
+	mixin SimpleCompare;
 }
 
 class VarExpression : Expression
 {
 	string var;
 	mixin SimpleConstructor;
-	mixin SimpleCompare; // do not take "pos" into account
+	mixin SimpleCompare;
 }
 
 class AssignExpression : Expression
 {
 	Expression lhs;
 	Expression rhs;
 	mixin SimpleConstructor;
-	mixin SimpleCompare; // do not take "pos" into account
+	mixin SimpleCompare;
 }
 
 class FuncallExpression : Expression
 {
 	Expression   fun;
 	Expression[] args;
 	this(immutable LexPosition pos, Expression fun, Expression[] args...)
 		{ super(pos); this.fun=fun; this.args=args.dup; }
-	mixin SimpleCompare; // do not take "pos" into account
+	mixin SimpleCompare;
 }
 
 class FunLiteralExpression : Expression
 {
 	string[] params;
 	Program  funbody;
 	mixin SimpleConstructor;
-	mixin SimpleCompare; // do not take "pos" into account
+	mixin SimpleCompare;
 }

Index: polemy/tricks.d
==================================================================
--- polemy/tricks.d
+++ polemy/tricks.d
@@ -115,11 +115,11 @@
 
 /* [Todo] is there any way to clearnly implement "assert_compiles" and "assert_not_compile"? */
 
 /// Mixing-in the bean constructor for a class
 
-template SimpleConstructor()
+/*mixin*/ template SimpleConstructor()
 {
 	static if( is(typeof(super) == Object) || super.tupleof.length==0 )
 		this( typeof(this.tupleof) params )
 		{
 			static if(this.tupleof.length>0)
@@ -171,11 +171,11 @@
 	}) );
 }
 
 /// Mixing-in the MOST-DERIVED-member-wise comparator for a class
 
-template SimpleCompare()
+/*mixin*/ template SimpleCompare()
 {
 	override bool opEquals(Object rhs_) const
 	{
 		if( auto rhs = cast(typeof(this))rhs_ )
 		{
@@ -233,5 +233,38 @@
 		mixin SimpleCompare;
 	}
 	assert_throw!AssertError( new Temp(1,"foo") == new TempDummy(1,"foo") );
 	assert_throw!AssertError( new Temp(1,"foo") <= new TempDummy(1,"foo") );
 }
+
+/// Mixing-in a simple toString method
+
+/*mixin*/ template SimpleToString()
+{
+	override string toString()
+	{
+		string str = sprintf!"%s("(typeof(this).stringof);
+		foreach(i,mem; this.tupleof)
+		{
+			if(i) str ~= ",";
+			static if( is(typeof(mem) == std.bigint.BigInt) )
+				str ~= std.bigint.toDecimalString(mem);
+			else
+				str ~= sprintf!"%s"(mem);
+		}
+		return str ~ ")";
+	}
+}
+
+version(unittest) import std.bigint;
+unittest
+{
+	class Temp
+	{
+		int x;
+		string y;
+		BigInt z;
+		mixin SimpleConstructor;
+		mixin SimpleToString;
+	}
+	assert_eq( (new Temp(1,"foo",BigInt(42))).toString(), "Temp(1,foo,42)" );
+}