Smartcasts

[i582]

This issue tracks the status of smart casts in the linter.

Current

instanceof

Only works for the simple case:

if ($a instanceof Foo) {
   // $a has \Foo type
}

And at the moment the variable continues to have this type after the if block, which is a bug.
#370
#363
#339
#286
#253

isset

Only works for the simple case:

if (isset($a)) {
   // $a exists
}

#287

empty

Only works for the simple case:

if (!empty($a)) {
   // $a exists
}

is_T functions

Not yet implemented.

Planned

Support for negation, support for simple AND and OR.
All is_T functions.

#346