To map integers to doubles, use this:

db_map<int, double, ElementHolder<double> >;

To store a char* string with long keys, use this:

Use this for const char* strings:

To map one const string to another, use this type:

db_map<const char*, const char*, ElementHolder<const char*> >;

For and wchar_t* strings, _DB_STL_StoreElement() must be called following partial or total modifications before iterator movement, container::operator[] or iterator::operator*/-> calls. Without the _DB_STL_StoreElement() call, the modified change will be lost. If storing an new value like this:

*iterator = new_char_star_string;

the call to _DB_STL_StoreElement() is not needed.

Note that passing a NULL pointer to a container of char* type or passing a std::string with no contents at all will insert an empty string of zero length into the database.

The string returned from a container will not live beyond the next iterator movement call, container::operator[] or iterator::operator*/-> call.

1. For some old compilers, such as gcc3.4.6, the *iterator cannot be used with the ternary ? operator, like this:

   Even when var is the same type as the iterator’s value_type, the compiler fails to perform an auto conversion.

You can find example code demonstrating string storage in the and StlAdvancedFeaturesExample::storing_std_strings() methods.