~= call copy ctor?

[Namespace]

A other question:
How can i check if t is valid, after i call "clear"?

[code]
import std.stdio;

class Test {
public:
	this() {
		writeln("CTor");
	}

	~this() {
		writeln("DTor");
	}
}

void main() {
	Test t = new Test();

	clear(t);

	writeln("end main");
}
[/code]

If i write assert(t !is null); it fails, and if i write 
writeln(t); or assert(t); i get an access violation.