Re: [boost] [Beast] Questions Before Review

On 25/06/2017 22:48, Vinnie Falco via Boost wrote:

On Sun, Jun 25, 2017 at 2:36 PM, Niall Douglas via Boost wrote:

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Where you need to consume or produce arbitrary scatter-gather buffers, use gsl::span<T> or equivalent.

As gsl::span<> is only capable of representing ranges of elements contiguous in memory, it is not capable of representing the majority of Beast's buffer sequences. Examples:

Think gsl::span. Actually AFIO v2 uses gsl::span>, but that's to avoid the bounds check per buffer that gsl may do. In your case that bounds check won't be as important, so gsl::span makes lots of sense. Not least for all the extra automated static analysis you get for free.

...

I certainly can see that char iterators are going to get used a lot

Beast never templates on the character type. All operations on structured data (for example HTTP headers) are performed on a single contiguous memory buffer of chars. This is done for performance reasons.

Hmm. I find that highly surprising. I'd have thought that as the HTTP data comes in - in chunks - your code would work with discontiguous storage. Are you memory copying instead? Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/