The `VecTraits` class allows templated functions, methods, and classes to
treat type arguments uniformly as `Vec` types or to otherwise differentiate
between scalar and vector types. This only works for types that `VecTraits`
is defined for.
The `VecTraits` templated class now has a default implementation that will
be used for any type that does not have a `VecTraits` specialization. This
removes many surprise compiler errors when using a template that, unknown
to you, has `VecTraits` in its implementation.
One potential issue is that if `VecTraits` gets defined for a new type, the
behavior of `VecTraits` could change for that type in backward-incompatible
ways. If `VecTraits` is used in a purely generic way, this should not be an
issue. However, if assumptions were made about the components and length,
this could cause problems.
Fixes#589
You can often get compile errors when trying to get `Vec` attributes
from types that do not define `VecTraits`. This is of particular problem
when you create an object like `Vec` with a component that does not
define `VecTraits`. Make using these types safer by internally using
`SafeVecTraits`, which will gracefully handle types that do not have
`VecTraits`.
Whan an `UnknownArrayHandler` is constructed from an `ArrayHandle`, it uses
the `VecTraits` of the component type to construct its internal functions.
This meant that you could not put an `ArrayHandle` with a component type
that did not have `VecTraits` into an `UnknownArrayHandle`.
`UnknownArrayHandle` now no longer needs the components of its arrays to
have `VecTraits`. If the component type of the array does not have
`VecTraits`, it treats the components as if they are a scalar type.
In VTK-m we have a constant tension between minimizing the number of
types we have to compile for (to reduce compile times and library size)
and maximizing the number of types that our filters support.
Unfortunately, if you don't compile a filter for a specific array type
(value type and storage), trying to run that filter will simply fail.
To compromise between the two, added methods to `DataSet` and `Field`
that will automatically convert the data in the `Field` arrays to a type
that VTK-m will understand. Although this will cause an extra data copy,
it will at least prevent the program from failing, and thus make it more
feasible to reduce types.
Added a BaseComponentType to VecTraits that recursively finds the base
(non-Vec) type of a Vec. This is useful when dealing with potentially
nested Vec's (e.g. Vec<Vec<T, M>, N>) and you need to keep the structure
but know the base type.
Also added a couple of templates for keeping the structure but changing
the type. These are ReplaceComponentType and ReplaceBaseComponentType.
These allow you to create new Vec's with the same structure as the query
Vec but with differen component types.
Apparently, the Visual Studio 2015 has a bug where the result of a
decltype might not be considered a type. Attempt to get around this
problem by putting the decltype inside of a struct and then have the
using statement use the typename keyword. Hopefully if you literally say
that something is a typename, the compiler will treat it like a type
name.
HasVecTraits<T> is a template that will resolve to std::true_type if
VecTraits<T> is properly defined and std::false_type otherwise. This is
helpful when defining classes and methods that use VecTraits but you
still want them to compile if VecTraits does not exist.
Sandia National Laboratories recently changed management from the
Sandia Corporation to the National Technology & Engineering Solutions
of Sandia, LLC (NTESS). The copyright statements need to be updated
accordingly.
These structs behave much like Vec except that they work on a short C
array given to them rather than having the statically sized short array
defined within.
I expect to use this in the short term to help implement cell face
classes, but there are probably many other uses.
Change the VTKM_CONT_EXPORT to VTKM_CONT. (Likewise for EXEC and
EXEC_CONT.) Remove the inline from these macros so that they can be
applied to everything, including implementations in a library.
Because inline is not declared in these modifies, you have to add the
keyword to functions and methods where the implementation is not inlined
in the class.
These changes are basically to support some upcoming changes to
ArrayHandleZip. The major additions are an implementation of VecTraits
for Pair and an overloaded << operator to ostream for Pair.
I also had to declare the operator<< for Pair to be in Types.h. Under
some circumstances the operator has to either be declared before the
template is declared or declared in the vtkm namespace. (The reasons are
described at <http://clang.llvm.org/compatibility.html#dep_lookup> but I
still don't understand.) I tried adding it to the vtkm namespace, but
that caused several of the other operator<< to fail. Since there is no
way to guarantee that Pair.h is declared before, say, ArrayHandle.h, I
moved the implementation to Types.h.
Since I was moving operator<< to Types.h, I went ahead and moved the
TypeTraits and VecTraits to their respective headers. Since Pair is
declared (but not implemented) in Types.h, these templated classes can
be implemented without including Pair.h.
This class holds a Vec and exposes some number of components. The class
is used when you need a Vec of a size that is not known at compile time
but that a maximum length of reasonable size is known.
Some changes to the Vec class and VecTraits in anticipation of creating
Vec-like objects. The following changes are made:
* Add GetNumberOfComponents to Vec, which returns NUM_COMPONENTS.
* Likewise, all VecTraits have a GetNumberOfComponents method.
* The ToVec method in VecTraits is changed to CopyInto so that it can be
used when the length of the Vec-like is not known. CopyInto is also
added to Vec.
* VecTraits has a typedef named IsSizeStatic which is set to
VecTraitsTagSizeStatic when the number of components is known at compile
time and VecTraitsTagSizeVariable when the number of components is not
known until runtime.
On one of my compile platforms, GCC was giving conversion warnings from
any boost include that was not wrapped in pragmas to disable conversion
warnings. To make things easier and more robust, I created a pair of
macros, VTKM_BOOST_PRE_INCLUDE and VTKM_BOOST_POST_INCLUDE, that should
be wrapped around any #include of a boost header file.
Fix compile warnings that come up with the flags
-Wconversion -Wno-sign-conversion
This catches several instances (mostly in the testing framework) where
types are implicitly converted. I expect these changes to fix some of
the warnings we are seeing in MSVC.
I was going to add these flags to the list of extra warning flags, but
unfortunately the Thrust library has several warnings of these types,
and I don't know a good way to turn on the warnings for our code but
turn them off for Thrust.