compile error when using two typename in template class

Question

I am using Arduino 1.8.5 ide. I am just creating a class with two typename which name is "Map". This class takes all int and String variations. Like;

class Map<int, int>;
class Map<int, String>;
class Map<String, int>;
class Map<String, String>;


Map<int, String> *list = new Map<int, String>();

If I create instance of this class like above in Main.ino file then everything is ok. But if I create it another file with .h extension which is "Test.h" then compilation fails. These are files;

Main.ino

#include "Map.h"
#include "Test.h"

Test *test = new Test();
Map<int, String> *list = new Map<int, String>();


void setup() {

}

void loop() {

}

Map.cpp

#include "Arduino.h"
#include "Map.h"

template<typename E, typename T> Map<E, T>::Map()
{

}


template class Map<int, int>;
template class Map<int, String>;
template class Map<String, int>;
template class Map<String, String>;

Map.h

#ifndef Map_h
#define Map_h

#include "Arduino.h"

template<typename E, typename T> class Map {

public:
    Map();
    ~Map();
};

#endif

Test.h

#ifndef _Test_h
#define _Test_h


#include "Arduino.h"
#include "Map.h"

class Test
{
public :
    Test();
    ~Test();
    Map<int, String> *list = new Map<int, String>();
};

#endif

Error is;

In file included from C:\Users\zafer\Desktop\Main\Main.ino:3:0:
Test.h:14: error: expected ';' at end of member declaration
  Map<int, String> *list = new Map<int, String>();

                                        ^

Test.h:14: error: expected unqualified-id before '>' token
  Map<int, String> *list = new Map<int, String>();

                                              ^

Test.h:14: error: wrong number of template arguments (1, should be 2)
  Map<int, String> *list = new Map<int, String>();

                                   ^

In file included from C:\Users\zafer\Desktop\Main\Main.ino:2:0:
Map.h:6: error: provided for 'template<class E, class T> class Map'
 template<typename E, typename T> class Map {

                                        ^
exit status 1
expected ';' at end of member declaration

Sorry, If it's been already resolved and I couldn't find it.

Thank you.

Answer 1

In this class declaration:

class Test
{
public :
    Test();
    ~Test();
    Map<int, String> *list = new Map<int, String>();
};

This line is wrong:

    Map<int, String> *list = new Map<int, String>();

You can't execute procedural code when declaring a class. That has to go into the constructor or some other function.

For example, this compiles without errors:

Test.h

#ifndef _Test_h
#define _Test_h


#include "Arduino.h"
#include "Map.h"

class Test
{
public :
    Test() { list = new Map<int, String>; } ;
    ~Test();
    Map<int, String> *list;
};

#endif