Reactive Extensions for C++
C++ CMake Other
Latest commit 7919ac2 Feb 21, 2017 @aargor aargor committed with kirkshoop Work-around for VS2017RC error C2672 building doc (#357)
When building RxCPP with the latest VS2017 RC, the compiler emits error
C2672 on compiling a method.

There was some off-line discussion (Kirk Shoop was included) about the
legitimacy of the error. In either case, I'd anticipate that the error
could hit in VS2017RTW, so I'm offering this PR.

The change is very targeted -- a natural question is if this error could
arise in the methods around retry. For that and further discussion, I
have to point you to my colleagues participating in the off-line
discussion; for this particular patch all I could do was confirm the
latest RC still needs it to build.

The Reactive Extensions for C++ (RxCpp) is a library of algorithms for values-distributed-in-time. The Range-v3 library does the same for values-distributed-in-space.

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Add Rx/v2/src to the include paths

lines from bytes

#include "rxcpp/rx.hpp"
namespace Rx {
using namespace rxcpp;
using namespace rxcpp::sources;
using namespace rxcpp::operators;
using namespace rxcpp::util;
using namespace Rx;

#include <regex>
#include <random>
using namespace std;
using namespace std::chrono;

int main()
    random_device rd;   // non-deterministic generator
    mt19937 gen(rd());
    uniform_int_distribution<> dist(4, 18);

    // for testing purposes, produce byte stream that from lines of text
    auto bytes = range(0, 10) |
        flat_map([&](int i){
            auto body = from((uint8_t)('A' + i)) |
                repeat(dist(gen)) |
            auto delim = from((uint8_t)'\r');
            return from(body, delim) | concat();
        }) |
        window(17) |
        flat_map([](observable<uint8_t> w){
            return w |
                    [](vector<uint8_t> v, uint8_t b){
                        return v;
                    }) |
        }) |
        tap([](vector<uint8_t>& v){
            // print input packet of bytes
            copy(v.begin(), v.end(), ostream_iterator<long>(cout, " "));
            cout << endl;

    // recover lines of text from byte stream

    auto removespaces = [](string s){
        s.erase(remove_if(s.begin(), s.end(), ::isspace), s.end());
        return s;

    // create strings split on \r
    auto strings = bytes |
        concat_map([](vector<uint8_t> v){
            string s(v.begin(), v.end());
            regex delim(R"/(\r)/");
            cregex_token_iterator cursor(&s[0], &s[0] + s.size(), delim, {-1, 0});
            cregex_token_iterator end;
            vector<string> splits(cursor, end);
            return iterate(move(splits));
        }) |
        filter([](const string& s){
            return !s.empty();
        }) |
        publish() |

    // filter to last string in each line
    auto closes = strings |
            [](const string& s){
                return s.back() == '\r';
            }) |
        Rx::map([](const string&){return 0;});

    // group strings by line
    auto linewindows = strings |
        window_toggle(closes | start_with(0), [=](int){return closes;});

    // reduce the strings for a line into one string
    auto lines = linewindows |
        flat_map([&](observable<string> w) {
            return w | start_with<string>("") | sum() | Rx::map(removespaces);

    // print result
    lines |

    return 0;

Reactive Extensions

The ReactiveX Observable model allows you to treat streams of asynchronous events with the same sort of simple, composable operations that you use for collections of data items like arrays. It frees you from tangled webs of callbacks, and thereby makes your code more readable and less prone to bugs.


Other language implementations


Cloning RxCpp

RxCpp uses a git submodule (in ext/catch) for the excellent Catch library. The easiest way to ensure that the submodules are included in the clone is to add --recursive in the clone command.

git clone --recursive
cd RxCpp

Building RxCpp

  • RxCpp is regularly tested on OSX and Windows.
  • RxCpp is regularly built with Clang, Gcc and VC
  • RxCpp depends on the latest compiler releases.

RxCpp uses CMake to create build files for several platforms and IDE's

ide builds


mkdir projects/build
cd projects/build
cmake -G"Xcode" ../CMake -B.

Visual Studio 2013

mkdir projects\build
cd projects\build
cmake -G"Visual Studio 14" ..\CMake -B.
msbuild rxcpp.sln

makefile builds


mkdir projects/build
cd projects/build
cmake -G"Unix Makefiles" -DCMAKE_BUILD_TYPE=RelWithDebInfo -B. ../CMake

Linux --- Clang

mkdir projects/build
cd projects/build
cmake -G"Unix Makefiles" -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_BUILD_TYPE=RelWithDebInfo -B. ../CMake

Linux --- GCC

mkdir projects/build
cd projects/build
cmake -G"Unix Makefiles" -DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++ -DCMAKE_BUILD_TYPE=RelWithDebInfo -B. ../CMake


mkdir projects\build
cd projects\build
cmake -G"NMake Makefiles" -DCMAKE_BUILD_TYPE=RelWithDebInfo -B. ..\CMake

The build only produces test and example binaries.

Running tests

  • You can use the CMake test runner ctest
  • You can run the test binaries directly rxcppv2_test_*
  • Tests can be selected by name or tag Example of by-tag

rxcppv2_test_subscription [perf]


RxCpp uses Doxygen to generate project documentation.

When Doxygen+Graphviz is installed, CMake creates a special build task named doc. It creates actual documentation and puts it to projects/doxygen/html/ folder, which can be published to the gh-pages branch. Each merged pull request will build the docs and publish them.

Developers Material

Contributing Code

Before submitting a feature or substantial code contribution please discuss it with the team and ensure it follows the product roadmap. Note that all code submissions will be rigorously reviewed and tested by the Rx Team, and only those that meet an extremely high bar for both quality and design/roadmap appropriateness will be merged into the source.

You will be prompted to submit a Contributor License Agreement form after submitting your pull request. This needs to only be done once for any Microsoft OSS project. Fill in the Contributor License Agreement (CLA).

Microsoft Open Source Code of Conduct

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact with any additional questions or comments.