} i get sometimes error like double pointer corruption, or terminate
} called after throwing an instance of std::length error. I am using
} std::string as key, any clue why these errors are coming up?

On Thu, Sep 17, 2009 at 11:01 AM, Craig Silverstein <csilv...@google.com> wrote:

> } i get sometimes error like double pointer corruption, or terminate
> } called after throwing an instance of std::length error. I am using
> } std::string as key, any clue why these errors are coming up?

> You will have to use placement new to initialize the strings.  Can you
> give a code sample of what you're doing now?

> craig

} here is the sample..
}
}  #define key_t std::string
}
} // loc_t is a structure with 3 unsigned integer fields
}  sparse_hash_map<key_t, loc_t> myMap;
} // for writing to file pointed by pointer fp
}  myMap.write_metadata(fp);
}  myMap.write_nopointer_data(fp);
} // for reading from file pointed by fp
} sparse_hash_map<key_t, loc_t> rMap;
}  rMap.read_metadata(fp);
}  rMap.read_nopointer_data(fp);
} // after reading and lookup is done
}  rMap.clear();

> } here is the sample..
> }
> }  #define key_t std::string
> }
> } // loc_t is a structure with 3 unsigned integer fields
> }  sparse_hash_map<key_t, loc_t> myMap;
> } // for writing to file pointed by pointer fp
> }  myMap.write_metadata(fp);
> }  myMap.write_nopointer_data(fp);
> } // for reading from file pointed by fp
> } sparse_hash_map<key_t, loc_t> rMap;
> }  rMap.read_metadata(fp);
> }  rMap.read_nopointer_data(fp);
> } // after reading and lookup is done
> }  rMap.clear();

> Ah, I see.  That won't work at all because string has pointers in it.
> read/write_nopointer is intended for Plain Old Data types.  You will
> need to do something more complicated.  Look at the documentation; it
> has an example of how to use read/write IO with non-trivial key/value
> types -- I forget the exact example, but it may even be for a string.

> craig

} I use the char* as the key, so it does not work either?