Re: cin.fail() , ignore() , clear()...
On Wed, 9 Feb 2011 07:46:49 CST, James Kanze <james.kanze@gmail.com>
wrote:
On Feb 7, 7:54 pm, TheGunslinger <mikiesrunsbaal....@sbcglobal.net>
wrote:
I have a programming assignment that is to utilize (a class in
OOP/C++)
cin.fail()
cin.ignore()
cin.clear()
These are to be used within a do/while if(cin.fail()) conditional.
In my 2010 C++ reference, I could only find a reference to one of
these functions.
Whereas in my 2000 reference, I can find documentation for all 3 and
a couple more.
My questions are:
1) Are these functions currently deprecated under the 2003 ISO
Standard and the ISO Draft to be confirmed and standardized this year?
No.
2) I can find numerous references to cin.fail() within the ISO draft
(I d/l'd a copy for reference.), BUT none for cin.clear() and
cin.ignore()??? Are these other functions being carried over strictly
for portability and compatibility issues for legacy program support?
I'm not sure what you're looking for. cin is an object, and the
functions are members of the class type of the object. Or, in
this case, of one of its base classes: try looking under
basic_ios.
--
James Kanze
James,
Thanks for your insights.
The problem was that since I couldn't find any references to these
functions in my newest reference, dated 2010.
However, in continuing my search for information, I was able find a
copy of the latest Draft of the C++ specifications that is to be
released later this year, and ALL the references to my questions
regarding deprecation, and your insights were, of course, answered in
there.
I do hope someone puts together a better reference than the one I paid
good money for this year. As it turns out, it was a complete waste of
money, IMHO.
I finally went with the following code snippet:
//-------------------------------------
do{
try{
cout<<"How many days to be rented?\n";
cin>>daysRented;
if(cin.fail()){
throw false;
}else{goodInput=true;}
}catch(bool IOerror){
goodInput=false;
cin.clear();
cin.ignore(20,'\n');
} //End try/throw/catch
}while(goodInput==false);
//--------------------------------------
which was most effective in catching bad user input errors.
IMHO,
MJR
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