Code Standards

New code should be based on C++17 and follow the C++ Core Guidelines to the best of our ability:

No “naked new/delete” in application code

Use PdmField / PdmChildField for PdmObjects which own other PdmObjects. Otherwise use smart pointers (std::unique_ptr, std::shared_ptr, cvf::ref).

Use the new C++14 creation rather than directly using new. I.e use:

auto object = std::make_unique<Object>();
auto cvfObject = cvf::make_ref<cvf::Object>();

rather than

std::unique_ptr ptr (new Object);
cvf::ref<cvf::Object> cvfObject = new cvf::Object;

PdmPointer should only be used for referencing objects owned somewhere else and not for ownership as it contains no reference counting. This policy will allow us to start using static code analysers which look for uses of new/delete.

Assignment to ChildFields and ChildArrayFields

A child field or child array field can be assigned from a std::unique_ptr.

i.e:

oilField->wellPathCollection = std::make_unique<RimWellPathCollection>();

rather than

oilField->wellPathCollection = new RimWellPathCollection

Remove deletion of child objects from destructors whenever you come across it

A child field or child array field does not need an explicit delete of the contained object. This is handled automatically by the field destructor. However the code base still contains some explicit deletes that can (and should be) be safely removed whenever you come across them.

Exception for Qt

Qt widgets and layouts takes over ownership of widgets assigned to them. It would thus be dangerous to pass a unique_ptr into it. The following is thus dangerous since the unique_ptr and layout both assumes ownership.

auto label = std::make_unique<QLabel>();
layout->addWidget(label.get());

However, the following is acceptable (and safer than using new, because you don’t risk leaks if you forget to assign a widget):

auto label = std::make_unique<QLabel>();
layout->addWidget(label.release());

Avoid passing bare pointers to methods which require the pointer to not be null.

Use

bool save(gsl::not_null<QString*> errorMsg);

instead of

bool save(QString* errorMsg)
{
  CAF_ASSERT(errorMsg);
  ...
}

gsl::not_null will issue a runtime-failure similar to CAF_ASSERT if a nullptr is assigned to it dynamically.

Use structured binding assignment for pairs and tuples.

Use

for (auto [startMD, endMD] : wellSegments())
{
...
}

not

for (auto segmentPair : wellSegments)
{ 
  auto startMD = segmentPair.first;
  auto endMD = segmentPair.second;
  ...
}