[boost] [lambda] how can I access structure member

Suppose I have the following structure: struct xy { int x, y; }; and the following vector: vector<xy> v(10); I want to use lambda library for find an item in the table. Let's say, with x member value equal to 10. Something like this doesn't work: pos = find_if(v.begin(), v.end(), _1.x == 10); How the above line should be written ? Rafal