Add a macro for allocating and populating a shallow copy of an array.
It is intended to replace a sequence like this:
ALLOC_ARRAY(dst, n);
COPY_ARRAY(dst, src, n);
With the less repetitve:
DUP_ARRAY(dst, src, n);
It checks whether the types of source and destination are compatible to
ensure the copy can be used safely.
An easier alternative would be to only consider the source and return
a void pointer, that could be used like this:
dst = ARRAY_DUP(src, n);
That would be more versatile, as it could be used in declarations as
well. Making it type-safe would require the use of typeof_unqual from
C23, though.
So use the safe and compatible variant for now.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
memmove(dst, src, st_mult(size, n));
}
+#define DUP_ARRAY(dst, src, n) do { \
+ size_t dup_array_n_ = (n); \
+ COPY_ARRAY(ALLOC_ARRAY((dst), dup_array_n_), (src), dup_array_n_); \
+} while (0)
+
/*
* These functions help you allocate structs with flex arrays, and copy
* the data directly into the array. For example, if you had: