Template instantiation Issues

[dany2704]

I am using library file Slist.h which has template declaration and definition.The library file is instantiated in the construtor
of mypgm.c(cpp file).The compiler throws an error which is mentioned at the bottom.

Slist.h
template <class Object>
class SList; // fwd declaration.
template <class Object>
class SListItr; // fwd declaration.
template <class Object>
class SListNode
{
SListNode( const Object &theElement = Object( ),
SListNode *n = NULL )
: element( theElement ), next( n ) { }

Object element;
SListNode *next;
friend class SList<Object>;
friend class SListItr<Object>;
};

template <class Object>
class SList
{
public:
SList( );
SList( const SList &rhs );
~SList( );
int isEmpty( ) const;
void makeEmpty( );
SListItr<Object> zeroth( ) const;
SListItr<Object> first( ) const;
const SList & operator=( SList &rhs );
int IsType() {return LinkedListType;};
private:
SListNode<Object> *header;
Object *ptr_Object;
};

//SList definition
template <class Object>
SList<Object>::SList( )
{
ptr_Object = new Object();
header = new SListNode<Object>;
}

// Copy constructor.
template <class Object>
SList<Object>::SList( const SList<Object> &rhs )
{
header = new SListNode<Object>;
*this = rhs;
}

// Destructor.
template <class Object>
SList<Object>::~SList( )
{
makeEmpty( );
delete ptr_Object;
delete header;
}

mypgm.c
class mypgm
{
public:
mypgm::mypgm()
{
ptr_dead_acc_list= new SList<String>; // ptr_dead_acc_list is of type SList<String>
}
};

String class details for your reference
class String
{
private:
char *_text;
friend class String_Iterator;
public:
// ctors and dtor
explicit String ();
explicit String (char *);
explicit String (int );
String (String& );
~String();

/////////////////
// conversions:
/////////////////
// to C-like type char *
operator char *() {return _text;}

/////////////////
// overloads:
/////////////////
// assignment String = String
String &operator=(String &);
}

Error:

SList.h: In constructor 'SList<Object>::SList() [with Object = String]':
mypgm.c:131: instantiated from here
SList.h:85: error: no matching function for call to 'String::String(String)'
String.h:27: note: candidates are: String::String(String&)
SList.h:41: error: in passing argument 1 of 'SListNode<Object>::SListNode(const Object&, SListNode<Object>*) [with Object = String]'
SList.h: In constructor 'SListNode<Object>::SListNode(const Object&, SListNode<Object>*) [with Object = String]':
SList.h:85: instantiated from 'SList<Object>::SList() [with Object = String]'
mypgm.c:131: instantiated from here
SList.h:42: error: passing 'const String' as 'this' argument of 'String::operator char*()' discards qualifiers
make: *** [all]

I feel that the arguments are not passed correctly during instantion,i have tried to resolve this ,but my steps are in vain
i am new to template concept.could you please help me to resolve this issue.
Thanks for looking into this

[ne555]

Your `String' class is not const-correct
ptr_dead_acc_list= new SList<String>; // ptr_dead_acc_list is of type SList<String> it should be a pointer

const SList & operator=( SList &rhs ); weird

[dany2704]

Thanks for the response.I have modified the copy constructor as constant,the compiler throws an error because calling a non-const method from a const method.Definition of copy cons

String::String(String const& string) 
{ _text = new char[string.length() + 1]; 
strcpy(_text,string); 
}

Error: String.c: In copy constructor 'String::String(const String&)':
String.c:error: passing 'const String' as 'this' argument of 'int String::length()' discards qualifiers
String.c:error:passing 'const String' as 'this' argument f 'String::operator char*()' discards qualifiers
String.c:51:invalid conversion from 'char*' to 'const char*'

Please help me to get rid of the error