Hi internals,
With PHP 8.5 deprecating the legacy cast syntax (boolean, double, integer, binary) in favor of bool, float, int, and string, I noticed that several legacy alias functions are still present in the language:
- is_double, which is an alias of is_float
- is_integer and is_long, both aliases of is_int
- doubleval, which is an alias of floatval
For reference, is_real was deprecated in PHP 7.4 and removed in 8.0.
Given the recent move toward clearer and more consistent type naming, it seems consistent to consider deprecating these remaining alias functions as well, since they reflect the same legacy terminology that the cast changes aim to clean up.
I found that this idea was mentioned before in a broader deprecation ideas thread targeting PHP 8, where variable handling function aliases such as is_double, is_integer and is_long were listed as candidates for potential cleanup. As far as I can tell, that discussion did not result in a dedicated RFC or vote on these specific aliases.
https://externals.io/message/103779#103805
Before drafting a formal RFC, I would like to confirm whether there have been more recent discussions or prior decisions on this topic that I may have missed. If not, I would be happy to prepare a concrete proposal for further discussion.
is_double, which is an alias of is_float
is_integer and is_long, both aliases of is_int
doubleval, which is an alias of floatval
For reference, is_real was deprecated in PHP 7.4 and removed in 8.0.
Hi Jordi,
The mailing list thread you linked is the only discussion I could see too.
That thread raised a valid concern, that the number of code search
matches is quite significant. We need a strong rationale to deprecate
a function. Functions that are not thread-safe, buggy, insecure,
overloaded with different signatures, or simply no longer necessary
(such as those resource close functions) are quite easy to argue that
deprecating them will lead to a positive outcome.
`is_double|integer|long` functions are purely aliases, and they have
been there in PHP practically forever. Code search results also yield
quite a lot of matches, so deprecating them will add a lot of work to
the package maintainers and users with little to no benefit. We
normally remove the deprecated functions by PHP 9.0, so for thousands
of packages, they cannot simply ignore these deprecations; they become
hard blockers to use PHP 9.0 (assuming you propose to remove them in
PHP 9.0).
Thank you,
Ayesh.
Hi Ayesh,
Thank you for checking for other discussions on this matter.
PHP 8.5 deprecating the legacy cast names like boolean, double, integer and binary in favor of bool, float, int and string feels like a pretty clear step toward cleaning up old type terminology. In that context, the remaining legacy alias functions stand out as inconsistent leftovers.
On the usage concern: the nice part here is that this is a pure rename with no semantic change. And compared to seven years ago, it also looks like these aliases are used a lot less in real world code, with most modern codebases already leaning on the canonical names. That makes the ecosystem impact meaningfully smaller than what the 2018 thread was reacting to.
Also, codebases that still use is_double are likely to also use the legacy (double) cast, which means they will have to migrate to (float) and is_float anyway. So the additional change from deprecating is_double and doubleval feels fairly limited.
I will proceed drafting an RFC so this can be discussed and decided properly.
ยทยทยท
On 21 Feb 2026 at 4:03 PM +0100, Ayesh Karunaratne ayesh@php.watch, wrote:
is_double, which is an alias of is_float
is_integer and is_long, both aliases of is_int
doubleval, which is an alias of floatval
For reference, is_real was deprecated in PHP 7.4 and removed in 8.0.
Hi Jordi,
The mailing list thread you linked is the only discussion I could see too.
That thread raised a valid concern, that the number of code search
matches is quite significant. We need a strong rationale to deprecate
a function. Functions that are not thread-safe, buggy, insecure,
overloaded with different signatures, or simply no longer necessary
(such as those resource close functions) are quite easy to argue that
deprecating them will lead to a positive outcome.
is_double|integer|long functions are purely aliases, and they have
been there in PHP practically forever. Code search results also yield
quite a lot of matches, so deprecating them will add a lot of work to
the package maintainers and users with little to no benefit. We
normally remove the deprecated functions by PHP 9.0, so for thousands
of packages, they cannot simply ignore these deprecations; they become
hard blockers to use PHP 9.0 (assuming you propose to remove them in
PHP 9.0).
Thank you,
Ayesh.