[C++] Improve buffer creation for typed data

[asfimport]

While looking into #2481 I noticed this pattern:

const uint8_t* bytes_array = reinterpret_cast<const uint8_t*>(input);
auto buffer = std::make_shared<Buffer>(bytes_array, sizeof(float)*input_length);

It's not the end of the world but seems a little verbose to me. It would be great to have something like this:

auto buffer = MakeBuffer<float>(input, input_length);

I couldn't find it, does it already exist somewhere? Any thoughts on the API? Potentially specializations to make a buffer out of a std::vector would also be helpful.

 

Reporter: Philipp Moritz / @pcmoritz
Assignee: Wes McKinney / @wesm

PRs and other links:

• GitHub Pull Request #2566

_{Note: This issue was originally created as ARROW-3157. Please see the migration documentation for further details.}

[asfimport]

Wes McKinney / @wesm:
How about something like this

template <typename T, typename SizeT>
static std::shared_ptr<Buffer> Wrap(const T* data, SizeT length) {
  return std::make_shared<Buffer>(reinterpret_cast<const uint8_t*>(data),
                                  static_cast<int64_t>(length) * sizeof(SizeT));
}

So we would write

auto buf = Buffer::Wrap(data, size);

[asfimport]

Wes McKinney / @wesm:
Issue resolved by pull request 2566
#2566