BSON_APPEND_ARRAY_FROM_VECTOR(3)

💅 BSON_APPEND_ARRAY_FROM_VECTOR(3) 💅

okay so bestie, this one lives in the libbson manual, and it's literally about turning a Vector into a plain old BSON Array 🦋 stay with me, it's not as scary as the name looks.

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✨ SYNOPSIS ✨

#define BSON_APPEND_ARRAY_FROM_VECTOR(b, key, iter) \
   bson_append_array_from_vector (b, key, (int) strlen (key), iter)

bool
bson_append_array_from_vector (bson_t *bson,
                               const char *key,
                               int key_length,
                               const bson_iter_t *iter);

so there's the cute little macro shortcut up top 👆 (it just does the strlen (key) for you, iykyk) and the real function underneath. both, verbatim, no notes. 🎀

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🌸 PARAMETERS 🌸

• bson — a bson_t. that's the doc you're writing into, the main character 💅
• key — an ASCII C string holding the name of the field. name your child!!
• key_length — how long key is, in bytes. or pass -1 and it'll figure it out with strlen() all on its own, lowkey iconic 🙈
• iter — a bson_iter_t pointing to any supported BSON Binary Vector subtype field. yes, any supported one, okurrr ⭐

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🦋 DESCRIPTION 🦋

the whole vibe: it converts the Vector that iter is pointing at into a plain BSON Array, and writes it to bson under the name key.

that's it. that's the function. vector in, array out, slay ✨

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👑 RETURNS 👑

it returns true if the operation was applied successfully. success!! we love to see it 💖

but ngl, it can fail too, and here's exactly when (no cap, memorize these):

• if appending the array grows bson larger than INT32_MAX 😭 (yeah, that's the ceiling, respect it)
• or if iter doesn't point to a valid recognized Vector type 💀

fr fr, if your iter is pointing at some random thing that isn't a legit recognized Vector, this function is gonna be like "not my problem" and fail.

🌈 SEE ALSO 🌈

• bson_array_builder_append_vector_elements()

go read that one next, bestie, it's giving related 🫶

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🎀 AUTHOR 🎀

MongoDB, Inc — yes, the whole company. collectively. as a treat 💜

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⭐ COPYRIGHT ⭐

2009-present, MongoDB, Inc. — protect it, it's theirs 👑

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and that's the page, babe 💅 this was 2.5.6 of libbson, dated Oct 09, 2026 — go forth and convert those vectors, you've got this 🦋✨