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Subject: Re: [PHP-DEV] make casts more strict in PHP 7
From: rowan.collins@gmail.com (Rowan Collins)

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"...

-- 
Rowan Collins
[IMSoP]