Rename sample_source -> sample.
Use std::string as type of argument to openmc_create_source.
Use reinterpret_cast when accessing dlsym.
Also moves check for dlerror to be before the attempt to create the
source (avoids null reference if fails) and capture error message
before dlclose, so that the error message is still available.
Formatting updates and some refactoring for examples and tests.
Custom sources are now created only through the new class-based method,
which supports parameterization.
New method also slightly adjusted to create the source as managed by a
unique_ptr.
Examples and tests updated to align with this approach.
Documentation updated.
In the existing custom_source implementation, the source will only be
created once. This is much more efficient than the custom serialized
source, where each sampling will create a new instance of the class.
As there could be many samples, this introduces an overhead,
particularly if the operations to instantiate the class are not trivial.
This implementation defines an abstract class, which is then used by the
custom classes to allow the custom serialized class to be created based
on the plugin, sampled from, and then destroyed.
Update documentation and test to reflect this.
Changes the implementation of the serialization to be on an attribute of
the source XML element within settings.xml. This removes the need for a
new file containing the serialization.
Parameters are provided as a key-value string, separated by a comma and
a space, although the implementation can change this is required.
Change example values to align with existing custom_source to make
comparisons easier.
Update documentation to be consistent.
The previous implementation had each sampling run reading from the
serialized file. This introduced a large I/O overhead and the
performance was much slower than the equivalent run with the
unserialized source.
Updates the SourceDistribution to optionally look for a function
template accepting char* as the second argument.
If serialization is defined as an attribute on the source element
provided in the settings.xml then the new form with serialization will
be used. Otherwise the existing form to load the custom source as-is
from the library will be used.
