Sorting a map on Non-key Data

[Mike Copeland]

I need to sort a map structure on an element that's not the storage
key. Here's the structure declaration:

struct CSTYPE
{ // City/State Record
string csKey; // City/State "Key"
string csString; // City & State data
} extern workCS;
typedef map<string, CSTYPE> CSINFO;
CSINFO cityStInfo;
map<string, CSTYPE>::iterator csIter;

The element I'm storing the map is csString, but once the map is
constructed I want to sort the structure by csKey. I was hoping that
there's a way to either reconstruct the map data or sort it so that I
could iterate through it in "csKey" order. Any thoughts? TIA

 

[acehreli]

   I need to sort a map structure on an element that's not the storage
key.  Here's the structure declaration:

struct CSTYPE
{                                         // City/State Record
        string csKey;                     // City/State "Key"
        string csString;                  // City & State data}       extern workCS;

typedef map<string, CSTYPE> CSINFO;
        CSINFO cityStInfo;
        map<string, CSTYPE>::iterator csIter;

   The element I'm storing the map is csString, but once the map is
constructed I want to sort the structure by csKey.  I was hoping that
there's a way to either reconstruct the map data or sort it so that I
could iterate through it in "csKey" order.  Any thoughts?  TIA

If the collection is not changing dynamically once it's constructed,
and you will be accessing it many times once it's sorted, then your
best bet is to use std::vector:

vector<CSTYPE> collection;
/* populate the collection here */

std::sort(collection.begin(), collection.end(),
your_sorting_function);

Ali