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John Potter
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 Posted: Fri Jun 27, 2003 4:48 pm Post subject: Re: initializer form |
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On 26 Jun 2003 10:15:52 -0400, "Andrei Alexandrescu"
<SeeWebsiteForEmail (AT) moderncppdesign (DOT) com> wrote:
| Quote: | "John Potter" <jpotter (AT) falcon (DOT) lhup.edu> wrote in message
news:saljfvci4u0qura56gr7kbm69ldo4ernn7 (AT) 4ax (DOT) com...
Never use the assignment symbol for initialization, it confuses
too many beginners.
Sure I must've misunderstood something. I see nothing confusing about:
int i = 5;
float f = 6;
string s = "Wyda!";
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FAQ: Why aren't the default ctor and assignment operator called?
John
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llewelly
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| Posted: Sat Jun 28, 2003 11:26 pm Post subject: Re: initializer form |
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John Potter <jpotter (AT) falcon (DOT) lhup.edu> writes:
| Quote: | On 26 Jun 2003 10:15:52 -0400, "Andrei Alexandrescu"
[email]SeeWebsiteForEmail (AT) moderncppdesign (DOT) com[/email]> wrote:
"John Potter" <jpotter (AT) falcon (DOT) lhup.edu> wrote in message
news:saljfvci4u0qura56gr7kbm69ldo4ernn7 (AT) 4ax (DOT) com...
Never use the assignment symbol for initialization, it confuses
too many beginners.
Sure I must've misunderstood something. I see nothing confusing about:
int i = 5;
float f = 6;
string s = "Wyda!";
FAQ: Why aren't the default ctor and assignment operator called?
[snip] |
Unfortunately, for types convertible to bool, there is a place where
constructor style initialization cannot be used:
if(int i(foo)) //syntax error
{
/* ... */
}
if(int i= foo) //ok
{
/* ... */
}
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Ed Avis
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| Posted: Sun Jun 29, 2003 2:03 pm Post subject: Re: initializer form |
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llewelly <llewelly.at (AT) xmission (DOT) dot.com> writes:
| Quote: | Unfortunately, for types convertible to bool, there is a place where
constructor style initialization cannot be used:
if(int i(foo)) //syntax error
{
/* ... */
}
if(int i= foo) //ok
{
/* ... */
}
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That seems really unfortunate, given the mistake (made occasionally by
even experienced programmers) of writing = for == or vice versa. If
the first form were legal then compilers could warn about the second.
What syntactic problem arises if the constructor style is permitted?
--
Ed Avis <ed (AT) membled (DOT) com>
[ See http://www.gotw.ca/resources/clcm.htm for info about ]
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llewelly
Guest
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| Posted: Mon Jun 30, 2003 4:00 pm Post subject: Re: initializer form |
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Ed Avis <ed (AT) membled (DOT) com> writes:
| Quote: | llewelly <llewelly.at (AT) xmission (DOT) dot.com> writes:
Unfortunately, for types convertible to bool, there is a place where
constructor style initialization cannot be used:
if(int i(foo)) //syntax error
{
/* ... */
}
if(int i= foo) //ok
{
/* ... */
}
That seems really unfortunate, given the mistake (made occasionally by
even experienced programmers) of writing = for == or vice versa. If
the first form were legal then compilers could warn about the second.
What syntactic problem arises if the constructor style is permitted?
|
I do not know of any, except the most vexing parse, which is always an
issue with constructor style, in or out of an if. I think this
case was simply overlooked.
[ See http://www.gotw.ca/resources/clcm.htm for info about ]
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KIM Seungbeom
Guest
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| Posted: Tue Jul 01, 2003 8:19 am Post subject: Re: initializer form |
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Ed Avis <ed (AT) membled (DOT) com> wrote
| Quote: | llewelly <llewelly.at (AT) xmission (DOT) dot.com> writes:
Unfortunately, for types convertible to bool, there is a place where
constructor style initialization cannot be used:
if(int i(foo)) //syntax error
{
/* ... */
}
if(int i= foo) //ok
{
/* ... */
}
That seems really unfortunate, given the mistake (made occasionally by
even experienced programmers) of writing = for == or vice versa. If
the first form were legal then compilers could warn about the second.
|
What is the problem with the second approach?
If you use == instead of = by mistake, it will be a syntax error.
if (int i == foo) // error
{ /* ... */
| Quote: |
What syntactic problem arises if the constructor style is permitted?
|
I don't see any problem.
--
KIM Seungbeom <musiphil (AT) bawi (DOT) org>
[ See http://www.gotw.ca/resources/clcm.htm for info about ]
[ comp.lang.c++.moderated. First time posters: Do this! ]
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