#include <glas/concept/vector_expression.hpp>
#include <glas/concept/vector_collection.hpp>

namespace glas {

template <VectorExpression E, VectorCollection C>
  where std::SameType<typename E::size_type, typename C::size_type>
bool foo( C& c, E const& e ) {
  return c.size() == e.size() ;
}

struct bar2 {
  template <VectorExpression E, VectorCollection C>
    where std::SameType<typename E::size_type, typename C::size_type>
  bool operator() ( C& c, E const& e ) const {
    return c.size() == e.size() ;
  }
};

template <VectorExpression E, VectorCollection C>
  where std::SameType<typename E::size_type, typename C::size_type>
struct bar {
  bool operator() ( C& c, E const& e ) const {
    return c.size() == e.size() ;
  }
};

}

struct bar {
  template <class T>
    where std::EqualityComparable<T>
  bool operator() ( T const& t1, T const& t2 ) {
    return t1 == t2 ;
  }
} ;


template <class T>
  where std::EqualityComparable<T>
struct bar2 {
  bool operator() ( T const& t1, T const& t2 ) {
    return t1 == t2 ;
  }
} ;

int main() {
}