Apparently this does not return true for callback arguments to many of the internal functions, such as array_map and array_walk.
(PHP 5 >= 5.4.0, PHP 7, PHP 8)
ReflectionParameter::isCallable — Returns whether parameter MUST be callable
This function has been DEPRECATED as of PHP 8.0.0. Relying on this function is highly discouraged.
See the example below for an alternative way to derive this information.
This function is currently not documented; only its argument list is available.
This function has no parameters.
Example #1 PHP 8.0.0 equivalent
As of PHP 8.0.0, the following code will report if a type supports callables, including as part of a union.
<?php
function declaresCallable(ReflectionParameter $reflectionParameter): bool
{
$reflectionType = $reflectionParameter->getType();
if (!$reflectionType) return false;
$types = $reflectionType instanceof ReflectionUnionType
? $reflectionType->getTypes()
: [$reflectionType];
return in_array('callable', array_map(fn(ReflectionNamedType $t) => $t->getName(), $types));
}
?>Apparently this does not return true for callback arguments to many of the internal functions, such as array_map and array_walk.