- use allocator class to wrap the stream pointers instead of passing
them into ISstream, OSstream and using a dynamic cast to delete
then. This is especially important if we will have a bidirectional
stream (can't delete twice!).
STYLE:
- file stream constructors with std::string (C++11)
- for rewind, explicit about in|out direction. This is not currently
important, but avoids surprises with any future bidirectional access.
- combined string streams in StringStream.H header.
Similar to <sstream> include that has both input and output string
streams.
- inherit from std::iterator to obtain the full STL typedefs, meaning
that std::distance works and the following is now possible:
labelRange range(100, 1500);
scalarList list(range.begin(), range.end());
--
Note that this does not work (mismatched data-types):
scalarList list = identity(12345);
But this does, since the *iter promotes label to scalar:
labelList ident = identity(12345);
scalarList list(ident.begin(), ident.end());
It is however more than slightly wasteful to create a labelList
just for initializing a scalarList. An alternative could be a
a labelRange for the same purpose.
labelRange ident = labelRange::identity(12345);
scalarList list(ident.begin(), ident.end());
Or this
scalarList list
(
labelRange::null.begin(),
labelRange::identity(12345).end()
);
This uses a concept similar to what std::valarray and std::slice do.
A labelRange provides a convenient container for holding start/size
and lends itself to addressing 'sliced' views of lists.
For safety, the operations and constructors restricts the given input range
to a valid addressible region of the underlying list, while the labelRange
itself precludes negative sizes.
The SubList version is useful for patches or other things that have a
SubList as its parameter. Otherwise the UList [] operator will be the
more natural solution. The slices can be done with a labelRange, or
a {start,size} pair.
Examples,
labelList list1 = identity(20);
list1[labelRange(18,10)] = -1;
list1[{-20,25}] = -2;
list1[{1000,5}] = -3;
const labelList list2 = identity(20);
list2[{5,10}] = -3; // ERROR: cannot assign to const!
- Introduce writeList(Ostream&, label) method in various List classes to
provide more flexibility and avoid hard-coded limits when deciding if a
list is too long and should be broken up into multiple lines (ASCII only).
- The old hard-code limit (10) is retained in the operator<< versions
- This functionality is wrapped in the FlatOutput output adapter class
and directly accessible via the 'flatOutput()' function.
Eg,
#include "ListOps.H"
Info<< "methods: " << flatOutput(myLongList) << endl;
// OR
Info<< "methods: ";
myLongList.writeList(os) << endl;
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)
};
Oriented somewhat on dictionary methods.
Return the argument string associated with the named option:
Info<< "-foo: " << args.option("foo") << nl;
Return true if the named option is found
if (args.optionFound("foo")) ...
Return an IStringStream to the named option
old: value = readScalar(IStringStream(args.options()["foo"])());
newer: value = readScalar(args.optionLookup("foo")());
also: List<scalar> lst(args.optionLookup("foo")());
Read a value from the named option
newest: value = args.optionRead<scalar>("foo");
Read a value from the named option if present.
old: if (args.options().found("foo"))
{
value = readScalar(IStringStream(args.options()["foo"])());
}
new: args.optionReadIfPresent("foo", value);
Read a List of values from the named option
patches = args.optionReadList<word>("patches");
Didn't bother adding optionReadListIfPresent<T>(const word&), since it
probably wouldn't be common anyhow.
- Read a bracket-delimited list, or handle a single value as list of size 1.
Mostly useful for handling command-line arguments.
eg,
if (args.options().found("patches"))
{
patches = readList<word>(IStringStream(args.options()["patches"])());
}
can handle both of these:
-patches patch0
-patches \( patch1 patch2 patch3 \)
- The capitalization is consistent with most other template classes, but
more importantly frees up xfer() for use as method name without needing
special treatment to avoid ambiguities.
It seems reasonable to have different names for transfer(...) and xfer()
methods, since the transfer is occuring in different directions.
The xfer() method can thus replace the recently introduced zero-parameter
transfer() methods.
Other name candidates (eg, yield, release, etc.) were deemed too abstract.
- this should provide a slightly more naturally means to using transfer
constructors, for example
labelList list2(list1.transfer());
vs. labelList list2(xferMove(list1));
- returns a plain list where appropriate (eg, DynamicList, SortableList)
for example
labelList list2(dynList1.transfer());
vs. labelList list2(xferMoveTo<labelList>(dynList1));
