Re: [Boost-users] How to bind the first of a pair?

Meryl Silverburgh wrote:

I have a map with key is a pair: typedef map < pair, string> pairMapString;

pair key(1,3); map[key] = "one";

How can I create a binary function using boost lamba which check the first value of the pair of the key of the map?

void add(pairMapString;& myMap, int x) {

iterator& itr = find_if(myMap.begin(), myMap.end(), bind(equal_to < int >(), bind(&BlockDataPairMap::value_type::first::value_type::first, _1 ) , x) );

myMap.lower_bound( make_pair( x, INT_MIN ) ) should give you what you need in logarithmic time, if I'm not mistaken.