const reference life time extension, C++ (vc++)

const reference life time extension

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#include <iostream>
#include <sstream>

using namespace std;
using std::cout;
using std::endl;

class CSomeClass
{
protected:
    string m_Text;
public:
    CSomeClass(const string& NewText)
    {
        m_Text = NewText;
    }
    void ChangeText(const string& NewText)
    {
        m_Text = NewText;
    }
    //Getters
    string GetTextCopy() const
    {
        return m_Text;
    }
    string& GetTextRef()
    {
        return m_Text;
    }
    const string& GetTextRef() const
    {
        return m_Text;
    }
};

int main()
{
    CSomeClass SomeClass("OriginalText");
    string TextCopy = SomeClass.GetTextCopy(); //Ok, copying text
    cout << string("TextCopy: ") << TextCopy << endl;
    const string& ConstTextRef = SomeClass.GetTextRef(); //Ok, taking reference to original string inside SomeClass
    cout << "ConstTextRef: " << ConstTextRef << endl;
    const string& RefToCopy = SomeClass.GetTextCopy(); //Ok, taking cosnt reference to copy of string
    cout << "RefToCopy: " << RefToCopy << endl;
    SomeClass.ChangeText("ModifiedText");
    cout << "RefToCopy after modifying original string: " << RefToCopy << endl; //Still references old copy of string. That one has not been modified
    cout << "ConstTextRef after modifying original string: " << ConstTextRef << endl; //Still references the string that has now been changed
    const string& ConstTextRefAfterModification = SomeClass.GetTextCopy(); //Will now reference a new copy of the updated string
    cout << "ConstTextRefAfterModification: " << ConstTextRefAfterModification << endl;
    
    //What is then not allowed?
    string& NonConstRefToTemp = SomeClass.GetTextCopy();
    cout << "NonConstRefToTemp: " << NonConstRefToTemp << endl; //On VC++, this works just fine but gives a level 4 warning. Other compilers give a compile error as the standard dictates.

return 0;
}


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