Re: STL list Problems

From:

SG <s.gesemann@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Mon, 2 Mar 2009 06:31:55 -0800 (PST)

Message-ID:

<9be750b6-b39f-4d87-aa79-57976b50ce72@l16g2000yqo.googlegroups.com>

On 2 Mrz., 14:57, mrc2...@cox.net (Mike Copeland) wrote:

Here is how I've changed the code, but still I cannot get it to
compile:
#pragma warning (disable:4786)

Eew! What's that for? :-p

#include <iostream>
#include <list>
#include <string>
#include <algorithm>

using namespace std;

struct test
{
   int key;
   int count;
   string str;
   bool operator==(const test &rhs)
   {
      return rhs.key == key;
   }
} tWork;

Stay away from global (namespace scope) variables -- in this case:
tWork.

list<test> L;
list<test>::iterator qq;

see above

int main(void)
{
        char str[100];

        for (int ii = 1; ii <= 10; ii++)
        {
                tWork.count = 0, tWork.key = ii;
                sprintf(str, "Test string #%d", ii);

Avoid the C part of the languange when there are better C++
alternatives. Working with bare naked character arrays is usually
more error-prone than dealing with std::string objects (memory leaks,
heap corruption, buffer overflow, ...)

                tWork.str = str;
                L.push_back(tWork);
        } // for
        int jj = 5;
        qq = find(L.begin(), L.end(), jj); <== error here

"jj" is of type "int". You didn't supply an operator== which accepts
an object of type "test" on one side and an object of type "int" on
the other side.

The compiler generates the error (C2679 in VS6.0) stating that I h=

ave

no == comparison operator.

I'm not familiar with the error messages of VS6.0. But g++ would have
told you what kind of operator== function your program lacks.

Cheers!
SG