Re: [PATCH 5/5] cbtree.h: define cb_init() in terms of CBTREE_INIT

From: Phillip Wood <phillip.wood123@gmail.com>
To: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>, git@vger.kernel.org
Cc: "Junio C Hamano" <gitster@pobox.com>, "Jeff King" <peff@peff.net>,
	"Martin Ågren" <martin.agren@gmail.com>,
	"Johannes Sixt" <j6t@kdbg.org>
Subject: Re: [PATCH 5/5] cbtree.h: define cb_init() in terms of CBTREE_INIT
Date: Mon, 27 Sep 2021 10:13:50 +0100	[thread overview]
Message-ID: <ef724a3a-a4b8-65d3-c928-13a7d78f189a@gmail.com> (raw)
In-Reply-To: <patch-5.5-7e571667674-20210927T003330Z-avarab@gmail.com>

Hi Ævar

On 27/09/2021 01:39, Ævar Arnfjörð Bjarmason wrote:
> Use the same pattern for cb_init() as the one established in the
> recent refactoring of other such patterns in
> 5726a6b4012 (*.c *_init(): define in terms of corresponding *_INIT
> macro, 2021-07-01).
> 
> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
> ---
>   cbtree.h | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/cbtree.h b/cbtree.h
> index a04a312c3f5..dedbb8e2a45 100644
> --- a/cbtree.h
> +++ b/cbtree.h
> @@ -37,11 +37,12 @@ enum cb_next {
>   	CB_BREAK = 1
>   };
>   
> -#define CBTREE_INIT { .root = NULL }
> +#define CBTREE_INIT { 0 }
>   
>   static inline void cb_init(struct cb_tree *t)
>   {
> -	t->root = NULL;
> +	struct cb_tree blank = CBTREE_INIT;
> +	memcpy(t, &blank, sizeof(*t));
>   }

Slightly off topic but would this be a good site for a compound literal 
test balloon?

	*t = (struct cb_tree){ 0 };

Compound literals are in C99 and seem to have been supported by MSVC 
since 2013 [1].

Best Wishes

Phillip

[1] 
https://docs.microsoft.com/en-us/cpp/porting/visual-cpp-what-s-new-2003-through-2015?view=msvc-160#whats-new-for-c-in-visual-studio-2013

>   struct cb_node *cb_lookup(struct cb_tree *, const uint8_t *k, size_t klen);
> 