<s>
The	O
computer	O
programming	O
language	O
,	O
C#	B-Application
,	O
introduces	O
several	O
new	O
features	O
in	O
version	O
2.0	O
(	O
corresponding	O
to	O
the	O
3rd	O
edition	O
of	O
the	O
ECMA-334	B-Application
standard	O
and	O
the	O
.NET	O
Framework	O
2.0	O
)	O
.	O
</s>
<s>
For	O
example	O
,	O
the	O
feature	O
is	O
heavily	O
used	O
by	O
code-generating	O
user	O
interface	O
designers	O
in	O
Visual	B-Application
Studio	I-Application
.	O
</s>
<s>
file1.cs	O
:	O
</s>
<s>
file2.cs	O
:	O
</s>
<s>
Generics	B-Language
,	O
or	O
parameterized	B-Language
types	I-Language
,	O
or	O
parametric	O
polymorphism	O
is	O
a	O
.NET	O
2.0	O
feature	O
supported	O
by	O
C#	B-Application
and	O
Visual	O
Basic	O
.	O
</s>
<s>
Unlike	O
C++	O
templates	O
,	O
.NET	O
parameterized	B-Language
types	I-Language
are	O
instantiated	O
at	O
runtime	O
rather	O
than	O
by	O
the	O
compiler	O
;	O
hence	O
they	O
can	O
be	O
cross-language	O
whereas	O
C++	O
templates	O
cannot	O
.	O
</s>
<s>
On	O
the	O
other	O
hand	O
,	O
C#	B-Application
does	O
not	O
support	O
non-type	O
generic	O
parameters	O
.	O
</s>
<s>
Unlike	O
generics	B-Language
in	O
Java	O
,	O
.NET	O
generics	B-Language
use	O
reification	O
to	O
make	O
parameterized	B-Language
types	I-Language
first-class	O
objects	O
in	O
the	O
CLI	O
Virtual	O
Machine	O
,	O
which	O
allows	O
for	O
optimizations	O
and	O
preservation	O
of	O
the	O
type	O
information	O
.	O
</s>
<s>
Their	O
purpose	O
is	O
similar	O
to	O
that	O
of	O
modules	B-Architecture
in	O
many	O
procedural	O
languages	O
.	O
</s>
<s>
The	O
.NET	O
2.0	O
Framework	O
allowed	O
C#	B-Application
to	O
introduce	O
an	O
iterator	O
that	O
provides	O
generator	O
functionality	O
,	O
using	O
a	O
yield	O
return	O
construct	O
similar	O
to	O
yield	O
in	O
Python	O
.	O
</s>
<s>
As	O
a	O
precursor	O
to	O
the	O
lambda	O
functions	O
introduced	O
in	O
C#	B-Application
3.0	O
,	O
C	O
#2	O
.0	O
added	O
anonymous	O
delegates	O
.	O
</s>
<s>
These	O
provide	O
closure-like	O
functionality	O
to	O
C#	B-Application
.	O
</s>
<s>
Unlike	O
some	O
closure	B-Language
implementations	O
,	O
each	O
anonymous	O
delegate	O
instance	O
has	O
access	O
to	O
the	O
same	O
relative	O
memory	O
location	O
for	O
each	O
bound	O
variable	O
,	O
rather	O
than	O
to	O
the	O
actual	O
values	O
at	O
each	O
creation	O
.	O
</s>
<s>
This	O
provides	O
improved	O
interaction	O
with	O
SQL	O
databases	O
,	O
which	O
can	O
have	O
nullable	O
columns	O
of	O
types	O
corresponding	O
to	O
C#	B-Application
primitive	O
types	O
:	O
an	O
SQL	O
INTEGER	O
NULL	O
column	O
type	O
directly	O
translates	O
to	O
the	O
C#	B-Application
int	O
?	O
.	O
</s>
<s>
Nullable	O
types	O
received	O
an	O
improvement	O
at	O
the	O
end	O
of	O
August	O
2005	O
,	O
shortly	O
before	O
the	O
official	O
launch	O
,	O
to	O
improve	O
their	O
boxing	O
characteristics	O
:	O
a	O
nullable	O
variable	O
which	O
is	O
assigned	O
null	O
is	O
not	O
actually	O
a	O
null	O
reference	O
,	O
but	O
rather	O
an	O
instance	O
of	O
struct	B-Application
Nullablexxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx1	O
with	O
property	O
HasValue	O
equal	O
to	O
false	O
.	O
</s>
<s>
,	O
since	O
it	O
required	O
core-CLR	O
changes	O
affecting	O
not	O
only	O
.NET2	O
,	O
but	O
all	O
dependent	O
technologies	O
(	O
including	O
C#	B-Application
,	O
VB	O
,	O
SQL	O
Server	O
2005	O
and	O
Visual	B-Application
Studio	I-Application
2005	O
)	O
.	O
</s>
