stl - HowTo sort std::map? -

here map:

typedef std::map<int/*security id*/, positionmonth> portfoliomonth; 

where positionmonth structure, ex.:

struct positionmonth         {             nav::shares shares_;             nav::amount market_value_;              positionmonth(void)                 {}             positionmonth(const nav::amount& market_value                     , const nav::shares& shares)                 : market_value_(market_value)                 , shares_(shares)                 {}         }; 

question: how sort std::map second value key param (by market_value_, let int)? examples or links?

ps. boost methods not interested!

pps. i'm unable initialise std::map compare functor!

thanks help!

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my solution (or how did myself):

template<class t>     struct lesssecondccy         : std::binary_function<t,t,bool>     {         inline bool operator ()(const t& _left, const t& _right)         {             return _left.second.market_value_.currency() < _right.second.market_value_.currency();         }     }; 

and in function:

typedef std::pair<int/*security id*/, _entry> data_t; 

where _entry positionmonth

std::vector<data_t> vec(item.funds_end_.begin(), item.funds_end_.end()); std::sort(vec.begin(), vec.end(), nav::lesssecondccy<data_t>()); 

done!

there several options gamedev.net. down thread posting fruny.

aside: why not consider boost possible solution provider? it's respected, peer evaluated, documented solution professional c++ coders.