It always worked to trivially copy these classes, but the compiler did
not think so because copy constructors were defined. Change these
constructors to be default so that the compler can properly check
triviality.
For some reason some versions of the CUDA compiler would return true for
`is_trivially_copyable` on a `VariantUnion` even when the types of the
union caused the copy constructor to get deleted.
Solve the problem by using `AllTriviallyCopyable` instead of directly
caling `is_trivially_copyable` on the union.
Nvcc was having troubles resolving the return type of the overloaded
function to get a value out of a `VariantUnion`. Replace the
implementation with a class with specializations. This is more verbose,
but easier on the compiler.
Create a `VaraintUnion` that is an actual C++ `union` to store the data
in a `Variant`.
You may be asking yourself, why not just use an `std::aligned_union`
rather than a real union type? That was our first implementation, but
the problem is that the `std::aligned_union` reference needs to be
recast to the actual type. Typically you would do that with
`reinterpret_cast`. However, doing that leads to undefined behavior. The
C++ compiler assumes that 2 pointers of different types point to
different memory (even if it is clear that they are set to the same
address). That means optimizers can remove code because it "knows" that
data in one type cannot affect data in another type. To safely change
the type of an `std::aligned_union`, you really have to do an
`std::memcpy`. This is problematic for types that cannot be trivially
copied. Another problem is that we found that device compilers do not
optimize the memcpy as well as most CPU compilers. Likely, memcpy is
used much less frequently on GPU devices.
eadaf06f0 Set what string in Error::SetMessage
Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Nickolas Davis <nadavi@sandia.gov>
Merge-request: !2451
`vtkm::cont::Error` inherits from `std::exception`. As such, it has a
special `what` string that reports an error message in a standard way.
This is particularly useful when a `vtkm::cont::Error` exception remains
uncaught because the system will print the `what` string before
crashing.
Unfortunately, the `what` string was only being set in the `Error`
constructor that took a message. That is a problem for subclasses like
`ErrorCuda` that used the default constructor and then used
`SetMessage`. The `what` string did not get set in this case.
Change the behavior to capture the stack trace in the default
constructor and update the `what` string if a subclass uses
`SetMessage`.
486c5de95 TESTING: Set C++14 as minimum standard for install test
Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Li-Ta Lo <ollie@lanl.gov>
Merge-request: !2447
Although it makes sense to assume a pointer is `volatile` when doing an
atomic operation, the arguments to the `atomicCAS` overloads take
regular pointers. The overload resolution can fail if you use the
`volatile` keyword.
197a9b3ff fixed an oversight on the correct way to get CoordinateSystem.
Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Kenneth Moreland <kmorel@acm.org>
Merge-request: !2446
7572699b2 fix compiler warning
f57677081 did I miss more float?
e8d3325d8 use FloatDefault for density
1222ce5f9 override PrepareForExecution
59897dc31 add a missing word
45dd24ad7 reinstitute the counting of particles
d25eb7de7 more doc on the selection of scalar field and DivideByVolume
ff73723f5 fine tune the doc on the filter
...
Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Li-Ta Lo <ollie@lanl.gov>
Acked-by: Kenneth Moreland <kmorel@acm.org>
Merge-request: !2441
