Date: Sun, 19 Feb 2012 01:18:20 -0600 From: Mark Wiebe <mwwiebe@gmail.com> Subject: [Numpy-discussion] How a transition to C++ could work To: Discussion of Numerical Python <NumPy-Discussion@scipy.org> Message-ID: <CAMRnEmpVTmt=KduRpZKtgUi516oQtqD4vAzm746HmpqgpFXNqQ@mail.gmail.com> Content-Type: text/plain; charset="utf-8"
The suggestion of transitioning the NumPy core code from C to C++ has sparked a vigorous debate, and I thought I'd start a new thread to give my perspective on some of the issues raised, and describe how such a transition could occur.
First, I'd like to reiterate the gcc rationale for their choice to switch: http://gcc.gnu.org/wiki/gcc-in-cxx#Rationale
In particular, these points deserve emphasis:
- The C subset of C++ is just as efficient as C. - C++ supports cleaner code in several significant cases. - C++ makes it easier to write cleaner interfaces by making it harder to break interface boundaries. - C++ never requires uglier code.
I think they're trying to solve a different problem. I thought the problem that numpy was trying to solve is "make inner loops of numerical algorithms very fast". C is great for this because you can write C code and picture precisely what assembly code will be generated. C++ removes some of this advantage -- now there is extra code generated by the compiler to handle constructors, destructors, operators etc which can make a material difference to fast inner loops. So you end up just writing "C-style" anyway. On the other hand, if your problem really is "write lots of OO code with virtual methods and have it turned into machine code" (probably like the GCC guys) then maybe C++ is the way to go. Some more opinions on C++: http://gigamonkeys.wordpress.com/2009/10/16/coders-c-plus-plus/ Sorry if this all seems a bit negative about C++. It's just been my experience that C++ adds complexity while C keeps things nice and simple. Looking forward to seeing some more concrete examples. Cheers Ben