Question

for debugging I need to dump the contents of nested maps. I tried to describe this in the following code:

struct Foo
{       
   string name;
};

typedef std::map<string, Foo> MapFoo;

struct Bar  {
  string name;    
  MapFoo mapFoo;
};

typedef std::map<string, Bar> MapBar;

...

MapBar mapBar = init_mapBar(); 

const MapBar::const_iterator it = mapBar.find("name");

if ( mapBar.end() != it )
{
    return it->second;
}

Before I return it->second, I want to dump the contents of that item to cout. I am getting lost with the iterators when trying doing this. Thank you very much for some help or hints.

Answer 1

Write a function:

template <typename K, typename V, typename C>
void Dump( const map <K,V,C> & m ) {
    typename map <K,V,C>::const_iterator it = m.begin();
    while( it != m.end() ) {
        cout << it->first << " = " << it->second << endl;
        ++it;
    }
}

You can then say:

if ( mapBar.end() != it )
{
    Dump( it->second );
    return it->second;
}

and use it for dumping any other maps where K & V are types that have streaming operators available.