STL Map iterator compilation error

[Rakesh Kumar]

I am encountering the following issue with STL map iterator - wrapped
within a template. ( I am wrapping it withing a template since I want
to hide the map implementation from the user . At a later point - this
could be a custom hashmap (as opposed to rb-tree map that stl
provides ).

#include <string>
#include <map>
#include <iostream>

template<typename K, typename Vclass TestMap
{

public:
void insert(const std::pair<K, V& ap)
{
data.insert(ap);
}

void list()
{
std::map<K, V>::iterator it = data.begin();
//compiler errors here - error: expected
`;' before "it"

for (; it != data.end(); ++it)
{
std::cout << it->first << " --" << it->second << "\n";
}
}

private:
std::map<K, Vdata;
};

using std::string;

int main()
{
TestMap<std::string, intdata;

data.insert(std::pair<string, int >("Hello", 1));
data.insert(std::pair<string, int >("World", 1));
return EXIT_SUCCESS;
}
The compiler errors out with the following message.

test.cxx:17: error: expected `;' before "it"

Any idea if I am missing anything here.

[red floyd]

Rakesh Kumar wrote:

I am encountering the following issue with STL map iterator - wrapped
within a template. ( I am wrapping it withing a template since I want
to hide the map implementation from the user . At a later point - this
could be a custom hashmap (as opposed to rb-tree map that stl
provides ).

#include <string>
#include <map>
#include <iostream>

template<typename K, typename Vclass TestMap
{

public:
void insert(const std::pair<K, V& ap)
{
data.insert(ap);
}

void list()
{

typename std::map<K,V>::iterator it = data.begin();

std::map<K,V>::iterator is a dependent name, the compiler needs some
help to know it's a type.

std::map<K, V>::iterator it = data.begin();
//compiler errors here - error: expected
`;' before "it"

for (; it != data.end(); ++it)
{
std::cout << it->first << " --" << it->second << "\n";
}
}

private:
std::map<K, Vdata;
};

using std::string;

int main()
{
TestMap<std::string, intdata;

data.insert(std::pair<string, int >("Hello", 1));
data.insert(std::pair<string, int >("World", 1));
return EXIT_SUCCESS;
}
The compiler errors out with the following message.

test.cxx:17: error: expected `;' before "it"

Any idea if I am missing anything here.

[Rakesh Kumar]

On Nov 28, 4:26 pm, red floyd <[e-mail]:

>
typename std::map<K,V>::iterator it = data.begin();

std::map<K,V>::iterator is a dependent name, the compiler needs some
help to know it's a type.

Thanks redfloyd for the help.

Revised code that compiles:

#include <string>

#include <map>
#include <iostream>

template<typename K, typename Vclass TestMap
{

public:
void insert(const std::pair<K, V& ap)
{
data.insert(ap);
}

void list()
{
typename std::map<K, V>::iterator it = data.begin();
for (; it != data.end(); ++it)
{
std::cout << it->first << " --" << it->second << "\n";
}
}

private:
std::map<K, Vdata;
};

using std::string;

int main()
{
TestMap<std::string, intdata;

data.insert(std::pair<string, int >("Hello", 1));
data.insert(std::pair<string, int >("World", 1));
return EXIT_SUCCESS;
}