[Xapian-discuss] C++11

[Olly Betts]

I think we should seriously consider requiring a compiler with C++11
support for the next Xapian stable release series (i.e. Xapian 1.4.x).

There's not a firm timeline for when 1.4.0 will be out, but it's a
way off yet.  I need to sort out the blockers for 1.3.2 and actually
get that out, and then we need to sort through the ticket pile and
decide what has to get done.

C++11 adds a number of features which would make developing and
maintaining Xapian easier.  We could also safely drop various
workarounds for older compilers.

Both GCC and Clang seem to already fully support C++11 on the
compiler side, though the library support may not yet be complete.

This 3 month old blog post suggest MSVC and Intel's compiler both
support much of C++11, though not yet everything:

http://cpprocks.com/c1114-compiler-and-library-shootout/

So it's probably not reasonable to use C++11 features without
restriction, but there are plenty of useful things which are widely
supported, and the common subset should grow with time.

Some questions:

* Is anyone currently using Xapian with a C++ compiler without good
  C++11 support?

* If so, is there a reason why you can't switch to a compiler which
  has better support?

* We need to decide on a set of C++11 features which we can assume.
  I know people will be using GCC, clang, and MSVC.  What other
  compilers are people using, and can you point to some documentation
  of their level of C++11 support?

To be clear, I'm not suggesting anything should change for 1.2.x, so
if you're just using Xapian on an older system, you'll be able to
carry on following the 1.2.x release series.

Cheers,
    Olly