[PATCH v2 25/27] khash: name the structs that khash declares
- From
Elijah Newren via GitGitGadget <gitgitgadget@gmail.com>
- Date
- May 12, 2023, 07:04 UTC
- Message-ID
- <e0bfeb985562197f1f96b8735e8a15f9ae7a0b39.1683875072.git.gitgitgadget@gmail.com>
- In-Reply-To
- <pull.1525.v2.git.1683875068.gitgitgadget@gmail.com>
From: Elijah Newren <newren@gmail.com>
khash.h lets you instantiate custom hash types that map between two types. These are defined as a struct, as you might expect, and khash typedef's that to kh_foo_t. But it declares the struct anonymously, which doesn't give a name to the struct type itself; there is no "struct kh_foo". This has two small downsides:
- when using khash, we declare "kh_foo_t *the_foo". This is
unlike our usual naming style, which is "struct kh_foo *the_foo". - you can't forward-declare a typedef of an unnamed struct type in
C. So we might do something like this in a header file: struct kh_foo;
struct bar {
struct kh_foo *the_foo;
}; to avoid having to include the header that defines the real
kh_foo. But that doesn't work with the typedef'd name. Without the
"struct" keyword, the compiler doesn't know we mean that kh_foo is
a type.So let's always give khash structs the name that matches our conventions ("struct kh_foo" to match "kh_foo_t"). We'll keep doing the typedef to retain compatibility with existing callers.
Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Elijah Newren <newren@gmail.com> --- khash.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/khash.h b/khash.h index 56241e6a5c9..a0a08dad8b7 100644 --- a/khash.h +++ b/khash.h @@ -62,7 +62,7 @@ static inline khint_t __ac_X31_hash_string(const char *s) static const double __ac_HASH_UPPER = 0.77; #define __KHASH_TYPE(name, khkey_t, khval_t) \ - typedef struct { \ + typedef struct kh_##name { \ khint_t n_buckets, size, n_occupied, upper_bound; \ khint32_t *flags; \ khkey_t *keys; \
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