CODEWITHSUNDEEP
c++carraysperformancepointers
Evan
Evan

Reputation: 279

Pointer assignment versus pointer arithmetic

I'm working with a data set that varies in size from potentially very small, to as large as hundreds of millions.

When working with a contiguous data set, is there any difference in functionality or performance when assigning a new value to a pointer versus using pointer arithmetic to progress to my desired location?

For example, when progressing to the next member of the data, I could simply increment my pointer by one, or assign my working pointer to that memory address (assuming I already had it for whatever reason).

Operating under Windows using Visual Studio 2012 as a compiler.

Upvotes: 1

Views: 154

Answers (1)

Jacob Parker
Jacob Parker

Reputation: 2556

As for performance, according to Andrei Alexandrescu recently (see this link, there is a link to a video of a good talk he gave there) you should prefer indexing into an array over pointer arithmetic for contiguous accesses on modern machines.

However, there is one timeless rule for optimization: measure it! :)

Without more information I have nothing to say re: differences in functionality other than "no".

Upvotes: 2

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