Replaced all uses of complex Xfer class with C++11 "move" constructors and
assignment operators. Removed the now redundant Xfer class.
This substantial changes improves consistency between OpenFOAM and the C++11 STL
containers and algorithms, reduces memory allocation and copy overhead when
returning containers from functions and simplifies maintenance of the core
libraries significantly.
Until C++ supports 'concepts' the only way to support construction from
two iterators is to provide a constructor of the form:
template<class InputIterator>
List(InputIterator first, InputIterator last);
which for some types conflicts with
//- Construct with given size and value for all elements
List(const label, const T&);
e.g. to construct a list of 5 scalars initialized to 0:
List<scalar> sl(5, 0);
causes a conflict because the initialization type is 'int' rather than
'scalar'. This conflict may be resolved by specifying the type of the
initialization value:
List<scalar> sl(5, scalar(0));
The new initializer list contructor provides a convenient and efficient alternative
to using 'IStringStream' to provide an initial list of values:
List<vector> list4(IStringStream("((0 1 2) (3 4 5) (6 7 8))")());
or
List<vector> list4
{
vector(0, 1, 2),
vector(3, 4, 5),
vector(6, 7, 8)
};
