Re: what's the difference?
On 20 Apr., 01:47, "marcin.sfi...@gmail.com" <marcin.sfi...@gmail.com>
wrote:
On 17 Kwi, 22:09, Jonathan Lee <cho...@shaw.ca> wrote:> In practice, I prefer the second, pass by reference, where I have the
option. I do this for type safety. A reference cannot be null, so I
don't need to check for that (unlike a pointer). Also a reference is a
complete object. A pointer can be messed with and made to point to
something other than MyClass. A reference _is_ a MyClass.
Saying that reference cannot be null is misleading. For example:
void function(MyClass& obj) {
obj.method();
}
MyClass* obj = nullptr;
... // by mistake no valid address to MyClass object was assigned
... // to obj pointer
function(*obj); // there will be no runtime check preventing creation
// of reference from null pointer
Hold it right there, as you're causing undefined behaviour even before
you enter the body of the function.
void function(MyClass& obj) {
assert (&obj != nullptr);
Presuming that nullptr is defined as 0, the compiler is allowed to
ignore this assert as it cantever be true.
obj.method();
}
/Peter
--
[ See http://www.gotw.ca/resources/clcm.htm for info about ]
[ comp.lang.c++.moderated. First time posters: Do this! ]