make casts more strict in PHP 7

Hi!

No, no it would not. PHP’s explicit casts cannot fail, and there is
absolutely no good reason to change this. If people want strict
casting, we can add new functions or operators for that specifically.
But to break explicit casts and make them sometimes fail would cause
innumerable bugs and backwards-compatibility ideas.

I agree. If the developer explicitly states they want conversion, it
should be conversion. For implicit casts, some tightening may be ok, but
for explicit ones I think it would bring much more headaches than it's
worth.

Precisely, it would cause a vast amount of headaches for many projects.
Think of user input where you are expecting an integer and it must be a
positive integer (which would ultimately be a string); it is much faster to
do a quick check such as:

$foo = (int) $_GET['foo'];
if ($foo > 0) {
....
}

I'd personally not have to wrap more items around it due to a notice or
warning.

Andrea Faulds wrote (on 09/09/2014):

If people want strict casting, we can add new functions or operators
for that specifically.

I think this came up during the previous discussion, and I actually
think it would be quite nice to have some functions both to perform a
"strict"/"safe" cast (and raise E_CATCHABLE_ERROR or perhaps throw
TypeCastException), and to check if a variable can be thus cast
(validating integers is unnecessarily complicated at the moment).

Either:
mixed safe_cast(mixed $var, string $type)
boolean can_safe_cast(mixed $var, string $type)
e.g.
if ( can_safe_cast($_GET['i'], 'int') )
$i = safe_cast($_GET['i'], 'int');

Or, to avoid representing the type with a string arg, a whole set of
functions:
int safe_cast_int(mixed $var)
boolean can_safe_cast_int(mixed $var)
float safe_cast_float(mixed $var)
boolean can_safe_cast_float(mixed $var)
etc

The first avoids creating so many new functions, but perhaps some
constants should be defined for the argument, based on the values
returned by gettype():

PHP_TYPE_INT = "integer"
PHP_TYPE_FLOAT = "double"
PHP_TYPE_STRING = "string"
PHP_TYPE_ARRAY = "array"
PHP_TYPE_OBJECT = "object"
PHP_TYPE_RESOURCE = "resource"
PHP_TYPE_NULL = "NULL"

Of course, we'd then need to agree exactly which casts are considered
"safe"...

.oO(ext/filter) ?

--
Regards,
Mike

I think this came up during the previous discussion, and I actually think it would be quite nice to have some functions both to perform a "strict"/"safe" cast (and raise E_CATCHABLE_ERROR or perhaps throw TypeCastException), and to check if a variable can be thus cast (validating integers is unnecessarily complicated at the moment).

Either:
mixed safe_cast(mixed $var, string $type)
boolean can_safe_cast(mixed $var, string $type)
e.g.
if ( can_safe_cast($_GET['i'], 'int') )
$i = safe_cast($_GET['i'], 'int');

Or, to avoid representing the type with a string arg, a whole set of functions:
int safe_cast_int(mixed $var)
boolean can_safe_cast_int(mixed $var)
float safe_cast_float(mixed $var)
boolean can_safe_cast_float(mixed $var)
etc

The first avoids creating so many new functions, but perhaps some constants should be defined for the argument, based on the values returned by gettype():

PHP_TYPE_INT = "integer"
PHP_TYPE_FLOAT = "double"
PHP_TYPE_STRING = "string"
PHP_TYPE_ARRAY = "array"
PHP_TYPE_OBJECT = "object"
PHP_TYPE_RESOURCE = "resource"
PHP_TYPE_NULL = "NULL"

Of course, we'd then need to agree exactly which casts are considered "safe"…

You know, “int”, “float”, “string” etc. aren’t currently reserved words. We could add functions, or even make them reserved words and add internal functions (à la isset), so int(‘2’), float(‘2.0’), string(‘test’) etc.

Or perhaps class-like constructors? $a = new int('2'); ? Would kinda make sense given some people want to add methods to primitive types.

--
Andrea Faulds
http://ajf.me/