implementing begin()

[Nick Keighley]

Hi,

I'm trying to iterate over a container class. The class actually
contains a std::map, so I thought all I'd have to implement begin() and
end().

The example code has a problem in begin()

#include <string>
#include <map>

using namespace std;

class Inventory
{
public:
typedef map<string,string>::iterator iterator;

map<string,string>::iterator& begin()
{ return map_.begin(); } // *** ERROR HERE

private:
map<string,string> map_;
};

void f (string s)
{
}

int main (void)
{
Inventory invent;
Inventory::iterator i;

i = invent.begin();

return 0;
}

I can post the full text of the error message but it is rather
long. But in essense it says "cannot convert std::map...begin() to
std::_Rb_tree_iterator..."

I'm using gcc with the bloodshed environment.

Any suggestions greatfully accepted!
--
Nick Keighley

"Half-assed programming was a time-filler that, like knitting,
must date to the beginning of human experience."
"A Fire Upon The Deep" by Verne Vinge

[Kai-Uwe Bux]

Nick Keighley wrote:

#include <string>
#include <map>

using namespace std;

class Inventory
{
public:
typedef map<string,string>::iterator iterator;

map<string,string>::iterator& begin()
Make that:

map<string,string>::iterator begin()
{ return map_.begin(); } // *** ERROR HERE

private:
map<string,string> map_;
};

void f (string s)
{
}

int main (void)
{
Inventory invent;
Inventory::iterator i;

i = invent.begin();

return 0;
}

Best

Kai-Uwe Bux

[Nick Keighley]

Kai-Uwe Bux wrote:

Nick Keighley wrote:

<snip>

map<string,string>::iterator& begin()

Make that:

map<string,string>::iterator begin()

{ return map_.begin(); } // *** ERROR HERE

<snip>

yes! thankyou!
--
Nick Keighley