Aggregate Operators

Aggregate operators are operators that operate on the entire sequence of items emitted by an Observable. More...

Functions
template<typename Seed , typename Accumulator > requires (!utils::is_not_template_callable<Accumulator> || std::same_as<std::decay_t<Seed>, std::invoke_result_t<Accumulator, std::decay_t<Seed> &&, rpp::utils::convertible_to_any>>)
auto	rpp::operators::reduce (Seed &&seed, Accumulator &&accumulator)
	Apply a function to each item emitted by an Observable, sequentially, and emit the final value.
template<typename Accumulator >
auto	rpp::operators::reduce (Accumulator &&accumulator)
	Apply a function to each item emitted by an Observable, sequentially, and emit the final value.

Detailed Description

Aggregate operators are operators that operate on the entire sequence of items emitted by an Observable.

See also

https://reactivex.io/documentation/operators.html#mathematical

Function Documentation

reduce() [1/2]

template<typename Accumulator >

auto rpp::operators::reduce

(

Accumulator &&

accumulator

)

Apply a function to each item emitted by an Observable, sequentially, and emit the final value.

There is no initial value for seed, so, first value would be used as seed value and forwarded as is.

Parameters

accumulator

function which accepts seed value and new value from observable and return new value of seed. Can accept seed by move-reference.

Note

#include <rpp/operators/reduce.hpp>

Example

    rpp::source::just(1, 2, 3)
        | rpp::operators::reduce(std::plus<int>{})
        | rpp::operators::subscribe([](int v) { std::cout << v << std::endl; });
    // Output: 6

See also

https://reactivex.io/documentation/operators/reduce.html

reduce() [2/2]

template<typename Seed , typename Accumulator >
requires (!utils::is_not_template_callable<Accumulator> || std::same_as<std::decay_t<Seed>, std::invoke_result_t<Accumulator, std::decay_t<Seed> &&, rpp::utils::convertible_to_any>>)

auto rpp::operators::reduce	(	Seed &&	seed,
		Accumulator &&	accumulator )

Apply a function to each item emitted by an Observable, sequentially, and emit the final value.

Parameters

seed	initial value for seed
accumulator	function which accepts seed value and new value from observable and return new value of seed. Can accept seed by move-reference.

Note

#include <rpp/operators/reduce.hpp>

Example

    rpp::source::just(1, 2, 3)
        | rpp::operators::reduce(std::string{}, [](std::string&& seed, int v) { return std::move(seed) + std::to_string(v) + ","; })
        | rpp::operators::subscribe([](const std::string& v) { std::cout << v << std::endl; });
    // Output: 1,2,3,

See also

https://reactivex.io/documentation/operators/reduce.html

Examples

reduce.cpp.