SYNTAX EXAMPLES:
{func var="test $foo test"} <-- sees $foo
{func var="test $foo_bar test"} <-- sees $foo_bar
{func var="test $foo[0] test"} <-- sees $foo[0]
{func var="test $foo[bar] test"} <-- sees $foo[bar]
{func var="test $foo.bar test"} <-- sees $foo (not $foo.bar)
{func var="test `$foo.bar` test"} <-- sees $foo.bar

PRACTICAL EXAMPLES:
{include file="subdir/$tpl_name.tpl"} <-- will replace $tpl_name with value
{cycle values="one,two,`$smarty.config.myval`"} <-- must have backticks