...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::proto::fold::impl
template<typename Expr, typename State, typename Data>
struct impl : proto::transform_impl< Expr, State, Data > {
// types
typedef when<_, Sequence> X; // For exposition only
typedef when<_, State0> Y; // For exposition only
typedef typename boost::result_of<X(Expr, State, Data)>::type seq; // A Fusion sequence, for exposition only
typedef typename boost::result_of<Y(Expr, State, Data)>::type state0; // An initial state for the fold, for exposition only
typedef unspecified fun; // fun(v)(e,s) == when<_,Fun>()(e,s,v)
typedef typename fusion::result_of::fold<seq, state0, fun>::type result_type;
// public member functions
result_type operator()(typename impl::expr_param,
typename impl::state_param,
typename impl::data_param) const;
};
impl
public member functionsresult_type operator()(typename impl::expr_param expr, typename impl::state_param state, typename impl::data_param data) const;
Let seq
be
when<_, Sequence>()(expr, state, data)
,
let state0
be
when<_, State0>()(expr, state, data)
,
and let fun(data)
be an object such that
fun(data)(expr, state)
is equivalent to
when<_, Fun>()(expr, state, data)
. Then,
this function returns fusion::fold(seq, state0, fun(data))
.
Parameters: |
|