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| rfc:generics [2016/04/25 15:19] – mindplay | rfc:generics [2018/06/02 17:33] (current) – add github link mindplay |
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| * Status: Draft | * Status: Draft |
| * First Published at: http://wiki.php.net/rfc/generics | * First Published at: http://wiki.php.net/rfc/generics |
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| | **NOTE:** a newer version of this RFC may be under development [[https://github.com/mindplay-dk/php-generics-rfc|on GitHub]]. |
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| ===== Introduction ===== | ===== Introduction ===== |
| The first example is able to infer the type argument ''T'' as ''Hat'', because the type alias was used to type-hint the argument given for the ''$content'' parameter. | The first example is able to infer the type argument ''T'' as ''Hat'', because the type alias was used to type-hint the argument given for the ''$content'' parameter. |
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| The second example results in a ''TypeError'', because the type parameter ''T'' was explicitly defined as ''string''. (Note that, if we had not used ''declare(strict_types=1)'', and if ''Box'' had implemented ''__toString()'', this would have been acceptable, due to the default behavior of weak scalar type-checking.) | The second example results in a ''TypeError'', because the type parameter ''T'' was explicitly defined as ''string''. (Note that, if we had not used ''declare(strict_types=1)'', and if ''Box'' had implemented ''<nowiki>__toString()</nowiki>'', this would have been acceptable, due to the default behavior of weak scalar type-checking.) |
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| Note the addition of ''func_type_args()'', which returns a list of type-hints pertaining to the current generic function call or constructor invocation. This complements ''func_get_args()'' by providing the list of type-arguments as fully-qualified class-names. | Note the addition of ''func_type_args()'', which returns a list of type-hints pertaining to the current generic function call or constructor invocation. This complements ''func_get_args()'' by providing the list of type-arguments as fully-qualified class-names. |