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# bson_vector_packed_bit_view_t

A reference to mutable non-owned BSON Binary data holding a valid Vector of `packed_bit` element type.

## Synopsis

    #include <bson/bson.h>

    typedef struct bson_vector_packed_bit_view_t {
       /*< private >*/
    } bson_vector_packed_bit_view_t;

## Description

bson_vector_packed_bit_view_t is a structure that acts as an opaque reference to a block of memory that has been validated as a `packed_bit` vector.

It is meant to be passed by value and can be discarded at any time. The contents of the structure should be considered private.

The bson_t MUST be valid for the lifetime of the view and it is an error to modify the bson_t while using the view.

## Functions

- bson_vector_packed_bit_view_init()
- bson_vector_packed_bit_view_from_iter()
- bson_vector_packed_bit_view_as_const()
- bson_vector_packed_bit_view_length()
- bson_vector_packed_bit_view_length_bytes()
- bson_vector_packed_bit_view_padding()
- bson_vector_packed_bit_view_read_packed()
- bson_vector_packed_bit_view_write_packed()
- bson_vector_packed_bit_view_unpack_bool()
- bson_vector_packed_bit_view_pack_bool()

## Example

    // Fill a new vector with individual boolean elements
    {
        static const bool bool_values[] = {true, false, true, true, false};
        const size_t bool_values_count = sizeof bool_values / sizeof bool_values[0];

        bson_vector_packed_bit_view_t view;
        BSON_ASSERT (BSON_APPEND_VECTOR_PACKED_BIT_UNINIT (&doc, "from_bool", bool_values_count, &view));
        BSON_ASSERT (bson_vector_packed_bit_view_pack_bool (view, bool_values, bool_values_count, 0));
    }

    // Fill another new vector with packed bytes
    {
        static const uint8_t packed_bytes[] = {0xb0};
        const size_t unused_bits_count = 3;
        const size_t packed_values_count = sizeof packed_bytes * 8 - unused_bits_count;

        bson_vector_packed_bit_view_t view;
        BSON_ASSERT (BSON_APPEND_VECTOR_PACKED_BIT_UNINIT (&doc, "from_packed", packed_values_count, &view));
        BSON_ASSERT (bson_vector_packed_bit_view_write_packed (view, packed_bytes, sizeof packed_bytes, 0));
    }

    // Compare both vectors. They match exactly.
    {
        bson_iter_t from_bool_iter, from_packed_iter;
        BSON_ASSERT (bson_iter_init_find (&from_bool_iter, &doc, "from_bool"));
        BSON_ASSERT (bson_iter_init_find (&from_packed_iter, &doc, "from_packed"));
        BSON_ASSERT (bson_iter_binary_equal (&from_bool_iter, &from_packed_iter));
    }

See also

bson_append_vector_packed_bit_uninit()
bson_vector_packed_bit_const_view_t