inline namespace v5
{
namespace detail
{
////////////////////////////////////////////////////////////////////////////////////
// return_
using return_ = utility::identity;
////////////////////////////////////////////////////////////////////////////////////
template<typename Action>
struct call_action_
{
template<typename ...Args, typename A = Action>
constexpr auto operator()(Args &&... args) const
BOOST_PROTO_AUTO_RETURN(
BOOST_PROTO_TRY_CALL(as_action_<A>())(static_cast<Args &&>(args)...)
)
};
////////////////////////////////////////////////////////////////////////////////////
struct not_an_action
{};
////////////////////////////////////////////////////////////////////////////////////
template<typename BoolAction, typename ...Args>
struct eval_bool_action_
: std::integral_constant<
bool
, static_cast<bool>(
std::remove_reference<
decltype(call_action_<BoolAction>()(std::declval<Args>()...))
/// matches all \c Bx for \c x in <tt>[0,n)</tt>.
///
/// When applying <tt>and_\<B0,B1,...Bn\></tt> as a basic_action with an
/// expression \c e, state \c s and data \c d, it is
/// equivalent to <tt>(B0()(e, s, d),B1()(e, s, d),...Bn()(e, s, d))</tt>.
namespace detail
{
template<typename... Actions>
struct _block
: basic_action<_block<Actions...>>
{
template<typename ...Args>
constexpr auto operator()(Args &&... args) const
BOOST_PROTO_AUTO_RETURN(
BOOST_PROTO_TRY_CALL(utility::functional::back())(
(call_action_<Actions>()(static_cast<Args &&>(args)...), utility::void_)...
)
)
};
}
struct block
{};
namespace extension
{
template<typename... Actions>
struct action_impl<block(Actions...)>
: detail::_block<Actions...>
{};
}
// If the Tag action creates an expression, use functional::make_expr with
// a safe version of the deduced domain instead to avoid dangling references.
template<
typename ...Ts
, typename ThisTag = Tag
, typename MakeExpr =
functional::make_expr<
ThisTag
, domains::safe_domain_adaptor<deduce_domain>
>
, BOOST_PROTO_ENABLE_IF(
ThisTag::proto_arity_type::equal_to(sizeof...(Ts))
)
, BOOST_PROTO_ENABLE_IF(
v5::is_expr<
decltype(BOOST_PROTO_TRY_CALL(ThisTag())(std::declval<Ts>()...))
>::value
)
>
constexpr auto operator()(Ts &&...ts) const
BOOST_PROTO_AUTO_RETURN(
MakeExpr()(static_cast<Ts &&>(ts)...)
)
// If the Tag action doesn't create an expression, just use it as-is.
template<
typename ...Ts
, typename ThisTag = Tag
, BOOST_PROTO_ENABLE_IF(
ThisTag::proto_arity_type::equal_to(sizeof...(Ts))
)
