# Abstract interface:
interface InterA
{
	routine size()=>int
	routine serialize()=>string
	static routine statmeth()=>int
}

# Concrete interface for int:
interface InterA for int
{
	routine size(){
		io.writeln( "InterA<int>::size()", self )
		self += 789;
		io.writeln( "InterA<int>::size()", std.about(self) )
		io.writeln( "InterA<int>::size()", self.serialize() );
		return self + 1;
	}
	routine serialize() => string { return "abc" + (string) (int) self; }
	static routine statmeth()=>int { return 456 }
}

var a: InterA = 123       # a: value type InterA<int>; variable type InterA;
var b = (InterA) 123;     # b: value type InterA<int>; variable type InterA<int>;
var c: InterA<int> = 123  # c: value type InterA<int>; variable type InterA<int>;

io.writeln( a.size() )
io.writeln( "value", (int) a, a.statmeth() )

var d: int = c

# int is automatically converted to InterA<int>, where InterA or InterA<int>
# is expected:
var e: list<InterA<int>> = { 123 }

e.append(456)

var f: list<InterA> = { 678 }

f.append(456)

io.writeln( e, f )




interface InterB : InterA
{
	routine []( index: int ) => int
}

interface InterB for int : InterA<int>
{
	routine []( index: int ) => int {
		return (self & (1<<index)) >> index;
	}
}

var k = (InterB) 0x7ffeff;

f.append( k )

io.writeln( f, k[1] )

var h = (InterA) k;
io.writeln( std.about(h), h )

var m: InterA = k;
io.writeln( std.about(m), m )

var s = (InterA<int>) k;
io.writeln( std.about(s), s )