>> I use std::map for some application.  I would like to return a const
>> reference to some value with the operator[] function.  I have a public
>> method of the following form:

>> const value&  getValue( const int i ) const
>> {
>>          return myMap[i];
>> }

>> where myMap is of type std::map.  When I compile this with gcc, I get an
>> error due to the const method qualifier.  I can't figure out why?

> Map's operator[] isn't const.  It will modify the map (by inserting a
> default value) if the element does not exist.