Code style: should getter methods return pointers or references

[jianqiao]

Currently some classes (especially in the parser and the optimizer) have their getter methods return pointers (*) to objects while some return references (&) to objects. As Jignesh suggested, would it better if we follow certain style guide and uniform the style of the existing code? Say, only return pointers if the returning value can be NULL or is yielding ownership, otherwise return references.

[hbdeshmukh]

Hi @jianqiao

In some other modules, you can see a pattern -
For getter methods that won't modify the class member, we return a const reference we use
const Field& getField() const {}

For getter methods that allow modification of the class member, we return a pointer and the pattern is

Field* getFieldMutable() {}

We can perhaps have a third type when the getter releases ownership.

[cramja]

I've noticed that in the parser classes, there tends to be returning of const *. It may have been written this way because the SQL_ERROR macros in the parser/optimizer take pointers instead of references.

However there are some cases where const & are returned, in which case, if they are later used in the SQL_ERROR macro, they use the address of operator (&aReference) to essentially recover the pointer which seems a little dubious.