Re: Questions about chapter 11 (Operator Overloading) of TC++PL.

From:
 Rajesh S R <SRRajesh1989@gmail.com>
Newsgroups:
comp.lang.c++
Date:
Tue, 23 Oct 2007 18:35:18 -0000
Message-ID:
<1193164518.044045.219590@q5g2000prf.googlegroups.com>
On Oct 23, 2:09 pm, anon <a...@no.no> wrote:

Wayne Shu wrote:

Hi everyone, I am reading B.S. 's TC++PL (special edition).
When I read chapter 11 Operator Overloading, I have two questions.

1. In subsection 11.2.2 paragraph 1, B.S. wrote "In particular,
operator =, operator[], operator(), and operator-> must be nonstatic
member function; this ensures that their first operands will be
lvalues". I know that these operators must be nonstatic member
functions, but why this ensure their first operands will be lvalues?
e.g.
class foo
{
    int i;
public:
    foo & operator = (int ii) { i = ii; return *this; }


The first operant is ii.

};

foo bar() { return foo(); }

bar() = 10;


I wonder if this is legal?
The above statement is equivalent to:

bar().operator=(10);

bar() produces a temporary object of type foo. Its member is modified
by the above statement. Is it legal to change the value of temporary
objects created in a full expression, as pre C++ standards?
Some more clarifications are:
Can I evaluate the address of such temporary objects?
I mean, can I do:
std::cout << &bar();

Please give me the relevant sections of C++03 which deals with the
temporary objects created within a full expression.

Thanks in advance for your response.

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