Обсуждение: What about a castNode() macro?

Hi,

There's a repeated pattern of

Assert(IsA(ptr, nodetype));
foo = (nodetype *) ptr;

how about adding a castNode() that combines those? Something like:

#if !defined(USE_ASSERT_CHECKING)

#define castNode(nodeptr,_type_) \((_type_ *) (nodeptr))

#elif defined(__GNUC__)

#define castNode(nodeptr,_type_) \((_type_ *) ({ \    Node   *_result; \    _result = nodeptr; \    Assert(IsA(_result,
_type_));\    _result; \}))
 

#else

extern PGDLLIMPORT Node *newNodeMacroHolder;
#define castNode(nodePtr,_type_) \( \    newNodeMacroHolder = nodePtr, \    AssertMacro(IsA(newNodeMacroHolder,
_type_)),\    (_type_ *) newNodeMacroHolder \)
 

#endif

Greetings,

Andres Freund

-- Andres Freund                       http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
Services

Andres Freund <andres@2ndquadrant.com> writes:
> There's a repeated pattern of

> Assert(IsA(ptr, nodetype));
> foo = (nodetype *) ptr;

> how about adding a castNode() that combines those?

Doesn't really seem worth it.  The notational advantage is not great,
and to the extent that it were to touch a lot of places, the main outcome
would be pain for back-patching.
        regards, tom lane