🚀 go-pugleaf

Situation #1:

If some constructors are defined and the copy constructor isn't, g++
assumes that it doesn't exist, such that the call 

new classname(*this);

generates an error such as

Dictionary.c: In method `class Object* Dictionary::shallowCopy ()const ':
Dictionary.c:43: bad argument 0 for function `Dictionary::Dictionary
  (unsigned int (=  DEFAULT_CAPACITY ))' (type was class Dictionary)

(The code that produced this error is in the NIHCL v3.0, Object.h and
Dictionary.[ch]; I can send it to you on request)

Solution:  Declare classname(classname&) explicitly.

Situation #2:

If operator= is not defined for class A and class B calls A::operator=, an
error such as

Dictionary.c: In method `void  Dictionary::operator = (const class
  Dictionary&)':
Dictionary.c:51: no member function `Set::operator ='

is generated.  Although operator= is not inherited exactly, it still needs
to be defined implicitly.  Rules for generating the implicit operator= can
be found in the ARM, section 12.8.

Again, declaring operator=(classname&) explicitly solves the problem.

Again, the pertinent code is in Object.h, Dictionary.[ch] and Set.h.  In
fact, the operator= that should be called eventually is the one in ArrayOb.

I see this as a serious bug, albeit one with a simple workaround.  I also
believe that the two problems have a single cause...

--
Jason Merrill
jason@jarthur.claremont.edu