c++ - Copy vector of values to vector of pairs in one line -

i have following types:

struct x { int x; x( int val ) : x(val) {} }; struct x2 { int x2; x2() : x2() {} };  typedef std::pair<x, x2>      pair_t; typedef std::vector<pair_t>   pairs_vec_t; typedef std::vector<x>        x_vec_t; 

i need initialize instance of pairs_vec_t values x_vec_t. use following code , works expected:

int main() {   pairs_vec_t ps;   x_vec_t xs; // not empty in production code    ps.reserve( xs.size() );    { // want change block 1 line code.     struct get_pair {       pair_t operator()( const x& value ) {          return std::make_pair( value, x2() ); }     };     std::transform( xs.begin(), xs.end(), back_inserter(ps), get_pair() );   }    return 0; } 

what i'm trying reduce copying block 1 line using boost::bind. code not working:

for_each( xs.begin(), xs.end(), boost::bind( &pairs_vec_t::push_back, ps, boost::bind( &std::make_pair, _1, x2() ) ) ); 

i know why not working, want know how make working without declaring functions , structs?

something this?

using boost::lambda; x2 x; transform(..., (bind(std::make_pair<x,x2>, _1, ref(x)))); 

i cant check @ moment, if recalled correctly memory, above valid.