error: expected expression

[narges-dipir]

error: expected expression for two lines in PolarCode.cpp in Neatbeans.ide . first for :

std::generate (std::begin(_channel_order_descending), std::end(_channel_order_descending), [&]{ return n_t++; });

and the same error for :

std::sort( std::begin(_channel_order_descending), std::end(_channel_order_descending), [&](int i1, int i2) { return channel_vec[_bit_rev_order.at(i1)] < channel_vec[_bit_rev_order.at(i2)]; } );

[JYFredPark]

include "functional" library