This package provides Hack wrappers for the $_GET, $_POST, $_REQUEST,
$_COOKIE, $_FILES and $_SERVER super globals that are type safe.
The reason for this is two fold:
This makes dealing with them in Hack code very annoying. In partial mode they
are treated as un-typed values to save on casting from mixed everytime you
want to use a value from one.
Given that the majority of sites will want to read from these super-globals at
some point, it makes sense to do so in a type-safe manner. That is what this
Due to the readwrite nature of the $_SESSION and $GLOBALS super-globals,
they are not supported by this package.