|  support |  documentation |  report a bug |  advanced search |  search howto |  statistics |  random bug |  login
Request #71758 can't initialize inline a pass-by-references variable parameter
Submitted: 2016-03-09 15:36 UTC Modified: 2021-11-12 13:48 UTC
Avg. Score:5.0 ± 0.0
Reproduced:1 of 1 (100.0%)
Same Version:1 (100.0%)
Same OS:1 (100.0%)
From: vittorio dot zamparella at gmail dot com Assigned:
Status: Wont fix Package: Scripting Engine problem
PHP Version: 7.0.4 OS:
Private report: No CVE-ID: None
View Add Comment Developer Edit
Welcome! If you don't have a Git account, you can't do anything here.
You can add a comment by following this link or if you reported this bug, you can edit this bug over here.
Block user comment
Status: Assign to:
Bug Type:
From: vittorio dot zamparella at gmail dot com
New email:
PHP Version: OS:


 [2016-03-09 15:36 UTC] vittorio dot zamparella at gmail dot com
While I perfectly understand why I cannot pass by reference a literal, I whish that I could initialize a variable in the same place where I pass it as a parameter.
MyFunction( $var2 = "two" );

I think it is more readable, understandable and inline with the syntax of the language.
Maybe I'm missing some symple syntactic sugar to work around this (apart from initializing the variable the line before).

I understand that the result of assignment is an anonimous literal with containing the just assigned value (hence the warning), but I think that the compiler could be just that little bit smarter to allow for such a syntax, since the semantic is perfectly clear: assign the literal to the variable, then pass the variable (and not its value to the function.
Also the algorithm is quite simple: if the actual parameter is a literal and a variable is expected, if the literal is the product of an assignment pass the left part of the assignment to the function.
Actually I don't know if the parser can trace back where a value is coming from.

Thank you for your comments and explanantions.

Test script:
function MyFunction (&$parameter) { 
    echo $parameter."\n";
$var1 = 'one';
MyFunction( $var1 );
MyFunction( $var2 = "two" );

Expected result:

Actual result:

Notice: Only variables should be passed by reference in /in/iJAlU on line 7


Add a Patch

Pull Requests

Add a Pull Request


AllCommentsChangesGit/SVN commitsRelated reports
 [2021-09-22 16:40 UTC]
-Package: Compile Warning +Package: Scripting Engine problem
 [2021-09-22 16:40 UTC]
> Maybe I'm missing some symple syntactic sugar to work around
> this […]

No, you don't.  However, I don't think this will be improved;
after all, there are not that much reasons to use references at
all, and in-out parameters might not be that common, either.
 [2021-11-12 13:48 UTC]
-Status: Open +Status: Wont fix
 [2021-11-12 13:48 UTC]
I'll just go ahead and mark this as Won't Fix. We generally have no interest in making use of references more ergonomic, and rules around reference usage are going to become stricter rather than more lenient over time. Case in point, the sample code throws an Error exception in PHP 8.0.

Use of references is discouraged unless unavoidable, and I'm really hard pressed to think of a legitimate use-case for reference where the ability to perform an inline assignment would be important.
PHP Copyright © 2001-2022 The PHP Group
All rights reserved.
Last updated: Mon Jul 04 21:05:45 2022 UTC