- improves flexibility. Can tag a tmp as allowing non-const access to
the reference and skip additional const_cast in following code. For
example,
tmp<volScalarField> tfld(nullptr);
auto* ptr = getObjectPtr<volScalarField>("field");
if (ptr)
{
tfld.ref(*ptr);
}
else
{
tfld.reset(volScalarField::New(...));
}
auto& fld = tfld.ref();
ENH: renamed tmpNrc to refPtr
- the name 'refPtr' (reference|pointer) should be easier to remember
than tmpNrc (tmp, but non-ref-counted).
- provide tmpNrc typedef and header for code compatibility
NOTE
- in some places refPtr and tmp can be used instead of a
std::reference_wrapper for handling external references.
Unlike std::reference_wrapper, it can be default constructed
(holding nothing), whereas reference_wrapper may need a dummy
reference. However, the lifetime extension of references _may_ be
better with reference_wrapper.