Pointers and references: Difference between revisions

=={{header|Nimrod}}==

There are two types of pointers in Nimrod. Safe, garbage-collected references and unsafe pointers.

Create a safe reference:

<lang nimrod>type Foo = ref object

x, y: float

var f: Foo

new f</lang>

Accessing the reference:

<lang nimrod>echo f[]</lang>

When accessing values the dereference operator [] can be left out:

<lang nimrod>echo f[].x

f[].y = 12

echo f.y

f.x = 13.5</lang>

Create an (unsafe) pointer to an int variable:

<lang nimrod>var x = 3

var p = addr x</lang>

Access the integer variable through the pointer:

<lang nimrod>echo p[]

p[] = 42</lang>

Change the pointer to refer to another object:

<lang nimrod>var y = 12

p = addr y</lang>

Change the pointer to not point to any object:

<lang nimrod>p = nil</lang>