dsl_arithmetic_5_factories.h

expression cst(int i) { return expression(i); };

expression var(id id) { return expression(id); };

expression add(std::vector<expression> const& rands)
{
   return expression(add_op<expression>{ rands });
}

expression mul(std::vector<expression> const& rands)
{
   return expression(mul_op<expression>{ rands });
}