private static <T> FactoryExpression<T> createConstructorProjection(RelationalPath<T> path) {
        Expression<?>[] exprs = path.getColumns().toArray(new Expression[0]);
        return Projections.<T>constructor((Class) path.getType(), exprs);
    }
{@code RelationalPathUtils} provides static utility methods for {@link RelationalPath} instances

@author tiwe
querydsl-sql/src/main/java/com/querydsl/sql/RelationalPathUtils.java