Re: [c-prog] problem with vector iterator

[Olufowobi Lawal]

Thanks, it sure worked. 
I thought if T was int, then 
vector<T>::iterator iter; becomes vector<int>iterator iter, which is a type 
itself, considering the fact it works when the function is not written as a 
template.

Anyway thanks, I guess I still have a lot to understand.
Lawal.O





________________________________
From: Jim Smith <jmclauri...@yahoo.com>
To: c-prog@yahoogroups.com
Sent: Tuesday, July 7, 2009 11:12:34 PM
Subject: Re: [c-prog] problem with vector iterator





bool isPresent=false;

vector<T>::iterator p;

In the code above the compiler does not know that vector<T>::iterator is a type 
unless you use typename. 

Example:

template <typename T>
bool isNumberInVector( vector<T>&v, T numToCheck)
{
bool isPresent=false;
typedef typename vector<T>::iterator Iter;
Iter p;
for(p=v.begin( );p!=v.end( );p++)
if((*p)==numToCheck ) isPresent=true;

return isPresent;

}

That should work.

Best Regards,
Jim Smith

E-mail: jmclaurin11@ yahoo.com

--- On Tue, 7/7/09, wolexzo2 <wolex...@yahoo. com> wrote:

From: wolexzo2 <wolex...@yahoo. com>
Subject: [c-prog] problem with vector iterator
To: c-p...@yahoogroups. com
Date: Tuesday, July 7, 2009, 12:28 AM

Below is a template of a function isNumberInVector.

I get errors about the iterator when I run this program.

errors such as

error: expected `;' before `p'

`p' was not declared in this scope

error: dependent-name `std::vector: :iterator' is parsed as a non-type, but 
instantiation yields a type

I don't get error when I simply make the function non-template and use 
vector<int> instead.

So What could be the cause?

Thanks,

Lawal. O

#include <iostream>

#include <string>

#include<cstdlib>

#include<vector>

using namespace std;

template <typename T>

bool isNumberInVector( vector<T>&v, T numToCheck)

{

bool isPresent=false;

vector<T>::iterator p;

for(p=v.begin( );p!=v.end( );p++)

if((*p)==numToCheck ) isPresent=true;

return isPresent;

}

int main(){

vector<int> vect;

for(int i=0;i<20;i++ )

if(i%2==0)

vect.push_back( i);

int number=4;

if(isNumberInVector (vect,number) )cout<<"Yes It is";

else cout<<"No it isn't";

}











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