rx-tap.hpp File Reference

inspect calls to on_next, on_error and on_completed. More...

#include "../rx-includes.hpp"

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Classes
struct	rxcpp::member_overload< tap_tag >

Namespaces
	rxcpp
	rxcpp::operators

Macros
#define	RXCPP_OPERATORS_RX_TAP_HPP

Functions
template<class... AN>
auto	rxcpp::operators::tap (AN &&...an) -> operator_factory< tap_tag, AN... >
	inspect calls to on_next, on_error and on_completed. More...

Detailed Description

inspect calls to on_next, on_error and on_completed.

Template Parameters

MakeObserverArgN...

these args are passed to make_observer.

Parameters

an	these args are passed to make_observer.

Returns

Observable that emits the same items as the source observable to both the subscriber and the observer.

Note

If an on_error method is not supplied the observer will ignore errors rather than call std::terminate()

Sample Code

    auto values = rxcpp::observable<>::range(1, 3).
        tap(
            [](int v){printf("Tap -       OnNext: %d\n", v);},
            [](){printf("Tap -       OnCompleted\n");});
    values.
        subscribe(
            [](int v){printf("Subscribe - OnNext: %d\n", v);},
            [](){printf("Subscribe - OnCompleted\n");});

Tap -       OnNext: 1
Subscribe - OnNext: 1
Tap -       OnNext: 2
Subscribe - OnNext: 2
Tap -       OnNext: 3
Subscribe - OnNext: 3
Tap -       OnCompleted
Subscribe - OnCompleted

If the source observable generates an error, the observer passed to tap is called:

    auto values = rxcpp::observable<>::range(1, 3).
        concat(rxcpp::observable<>::error<int>(std::runtime_error("Error from source"))).
        tap(
            [](int v){printf("Tap -       OnNext: %d\n", v);},
            [](std::exception_ptr ep){
                printf("Tap -       OnError: %s\n", rxu::what(ep).c_str());
            },
            [](){printf("Tap -       OnCompleted\n");});
    values.
        subscribe(
            [](int v){printf("Subscribe - OnNext: %d\n", v);},
            [](std::exception_ptr ep){
                printf("Subscribe - OnError: %s\n", rxu::what(ep).c_str());
            },
            [](){printf("Subscribe - OnCompleted\n");});

Tap -       OnNext: 1
Subscribe - OnNext: 1
Tap -       OnNext: 2
Subscribe - OnNext: 2
Tap -       OnNext: 3
Subscribe - OnNext: 3
Tap -       OnError: Error from source
Subscribe - OnError: Error from source

Macro Definition Documentation

#define RXCPP_OPERATORS_RX_TAP_HPP