// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.
#pragma once
/*! \file rx-any.hpp
\brief Returns an Observable that emits true if any item emitted by the source Observable satisfies a specified condition, otherwise false. Emits false if the source Observable terminates without emitting any item.
\tparam Predicate the type of the test function.
\param p the test function to test items emitted by the source Observable.
\return An observable that emits true if any item emitted by the source observable satisfies a specified condition, otherwise false.
Some basic any- operators have already been implemented:
- rxcpp::operators::exists
- rxcpp::operators::contains
\sample
\snippet exists.cpp exists sample
\snippet output.txt exists sample
\sample
\snippet contains.cpp contains sample
\snippet output.txt contains sample
*/
#if !defined(RXCPP_OPERATORS_RX_ANY_HPP)
#define RXCPP_OPERATORS_RX_ANY_HPP
#include "../rx-includes.hpp"
namespace rxcpp {
namespace operators {
namespace detail {
template<class... AN>
struct any_invalid_arguments {};
template<class... AN>
struct any_invalid : public rxo::operator_base<any_invalid_arguments<AN...>> {
using type = observable<any_invalid_arguments<AN...>, any_invalid<AN...>>;
};
template<class... AN>
using any_invalid_t = typename any_invalid<AN...>::type;
template<class T, class Predicate>
struct any
{
typedef rxu::decay_t<T> source_value_type;
typedef bool value_type;
typedef rxu::decay_t<Predicate> test_type;
test_type test;
any(test_type t)
: test(std::move(t))
{
}
template<class Subscriber>
struct any_observer
{
typedef any_observer<Subscriber> this_type;
typedef source_value_type value_type;
typedef rxu::decay_t<Subscriber> dest_type;
typedef observer<value_type, this_type> observer_type;
dest_type dest;
test_type test;
mutable bool done;
any_observer(dest_type d, test_type t)
: dest(std::move(d))
, test(std::move(t)),
done(false)
{
}
void on_next(source_value_type v) const {
auto filtered = on_exception([&]() {
return !this->test(v); },
dest);
if (filtered.empty()) {
return;
}
if (!filtered.get() && !done) {
done = true;
dest.on_next(true);
dest.on_completed();
}
}
void on_error(rxu::error_ptr e) const {
dest.on_error(e);
}
void on_completed() const {
if(!done) {
done = true;
dest.on_next(false);
dest.on_completed();
}
}
static subscriber<value_type, observer_type> make(dest_type d, test_type t) {
return make_subscriber<value_type>(d, this_type(d, std::move(t)));
}
};
template<class Subscriber>
auto operator()(Subscriber dest) const
-> decltype(any_observer<Subscriber>::make(std::move(dest), test)) {
return any_observer<Subscriber>::make(std::move(dest), test);
}
};
}
/*! @copydoc rx-any.hpp
*/
template<class... AN>
auto any(AN&&... an)
-> operator_factory<any_tag, AN...> {
return operator_factory<any_tag, AN...>(std::make_tuple(std::forward<AN>(an)...));
}
/*! \brief Returns an Observable that emits true if any item emitted by the source Observable satisfies a specified condition, otherwise false. Emits false if the source Observable terminates without emitting any item.
\tparam Predicate the type of the test function.
\param p the test function to test items emitted by the source Observable.
\return An observable that emits true if any item emitted by the source observable satisfies a specified condition, otherwise false.
\sample
\snippet exists.cpp exists sample
\snippet output.txt exists sample
*/
template<class... AN>
auto exists(AN&&... an)
-> operator_factory<exists_tag, AN...> {
return operator_factory<exists_tag, AN...>(std::make_tuple(std::forward<AN>(an)...));
}
/*! \brief Returns an Observable that emits true if the source Observable emitted a specified item, otherwise false. Emits false if the source Observable terminates without emitting any item.
\tparam T the type of the item to search for.
\param value the item to search for.
\return An observable that emits true if the source Observable emitted a specified item, otherwise false.
\sample
\snippet contains.cpp contains sample
\snippet output.txt contains sample
*/
template<class... AN>
auto contains(AN&&... an)
-> operator_factory<contains_tag, AN...> {
return operator_factory<contains_tag, AN...>(std::make_tuple(std::forward<AN>(an)...));
}
}
template<>
struct member_overload<any_tag>
{
template<class Observable, class Predicate,
class SourceValue = rxu::value_type_t<Observable>,
class Enabled = rxu::enable_if_all_true_type_t<
is_observable<Observable>>,
class Any = rxo::detail::any<SourceValue, rxu::decay_t<Predicate>>,
class Value = rxu::value_type_t<Any>>
static auto member(Observable&& o, Predicate&& p)
-> decltype(o.template lift<Value>(Any(std::forward<Predicate>(p)))) {
return o.template lift<Value>(Any(std::forward<Predicate>(p)));
}
template<class... AN>
static operators::detail::any_invalid_t<AN...> member(const AN&...) {
std::terminate();
return {};
static_assert(sizeof...(AN) == 10000, "any takes (Predicate)");
}
};
template<>
struct member_overload<exists_tag>
: member_overload<any_tag>
{
using member_overload<any_tag>::member;
template<class... AN>
static operators::detail::any_invalid_t<AN...> member(const AN&...) {
std::terminate();
return {};
static_assert(sizeof...(AN) == 10000, "exists takes (Predicate)");
}
};
template<>
struct member_overload<contains_tag>
{
template<class Observable, class T,
class SourceValue = rxu::value_type_t<Observable>,
class Enabled = rxu::enable_if_all_true_type_t<
is_observable<Observable>>,
class Predicate = std::function<bool(T)>,
class Any = rxo::detail::any<SourceValue, rxu::decay_t<Predicate>>,
class Value = rxu::value_type_t<Any>>
static auto member(Observable&& o, T&& value)
-> decltype(o.template lift<Value>(Any(nullptr))) {
return o.template lift<Value>(Any([value](T n) { return n == value; }));
}
template<class... AN>
static operators::detail::any_invalid_t<AN...> member(const AN&...) {
std::terminate();
return {};
static_assert(sizeof...(AN) == 10000, "contains takes (T)");
}
};
}
#endif