I like the fact that the C language lets you use binary arithmetic in an explicit way in your code, sometimes the use of the binary arithmetic can also give you a little edge in terms of performance; but since I started studying C++ i can't really tell how much i have seen the explicit use of something like that in a C++ code, something like a pointer to pointer structure or an instruction for jumping to a specific index value through the binary arithmetic.
Is the binary arithmetic still important and relevant in the C++ world?
How i can optimize my arithmetic and/or an access to a specific index?
What about the C++ and the way in which the bits are arranged according to the standard?
… or i have taken a look at the wrong coding conventions … ?
Best Answer
In short: No, it is not any good to use "binary arithmetic"(in sense the question asks it) or "C style" in C++.
What makes you believe bitwise arithmetic would be any faster really? You can throw your bitwise operations all over the code, but what would make it any faster?
The thing is, almost whatever trivial thing you're trying to solve, can be solved easier by the standard high-level features(including the standard library, STL and STL algorithms). In some specific cases you might indeed want to switch the individual bits, for example when working with bitmasks. Or storing very compact data, for example when writing a compression algorithm, a dense file format or working for example with embedded systems.
If you are concerned with performance, always write a simple and trivial algorithm first. Just make it work. Then, measure the time your algorithm takes with typical input. Now, if you at this point feel that it is too slow, only then you can try optimizing it by hand with these "bitwise arithmetic" tricks. And after done, measure if your code is any faster. The chances are that it is not, unless you really know what you are doing in that specific situation/case.
Frankly, the best way to understand about this kind of low-level constructs which deal with performance is to study assembly language. It really makes you realize that no, writing some bit-manipulating wizzcode is not any faster than using that
sort(begin(v),end(v)). Just because you operate at low level doesn't mean you operate fast. In general, Algorithms are more important than implementation details!Basically whatever the "C style" means, please, stay away from it when writing C++. They are two completely different languages. Don't mix them.
Bjarne Stroustrup gave a great talk about C++ style in Microsoft's GoingNative 2012 conference this February, please take a look: http://channel9.msdn.com/Events/GoingNative/GoingNative-2012/Keynote-Bjarne-Stroustrup-Cpp11-Style
Especially the parts between around 10 and 15 minutes are great, when he talks about old C-style code compared to modern C++ style.