L.s.,
I've just been looking in detail at the Partially Supported Callables
deprecation RFC:
https://wiki.php.net/rfc/deprecate_partially_supported_callables
The RFC explicitly excludes the `is_callable()` function and the
`callable` type from throwing deprecation notices.
The |is_callable()| function and |callable| type remain side-effect
free and do not throw a deprecation warning. They will continue to
accept these callables until support is removed entirely.
While I can fully support this for the `callable` type, I wonder if the
decision to not throw a deprecation on use in `is_callable()` is the
right one (though I understand the desire to keep it side-effect free).
Consider these code samples:
function foo(callable $callback) {}
foo('static::method');
This function call not throwing a deprecation is not problematic as in
PHP 9.0 the function will start throwing a TypeError.
if (is_callable('static::method')) {
static::method();
}
The second code sample, however, is problematic, as in PHP 9.0, the
behaviour of this code will be silently reversed for those callbacks
which would previously result in `is_callable()` returning true, which
makes this a potentially dangerous change without deprecation notice.
Would anyone care to enlighten me as to whether this was given due
consideration ?
Smile,
Juliette
