Added CMakeLists.txt to use with CMake builds.

[gyulalaszlo]

This has been so far only tested on OSX 10.9 with Clang.

• ZMQ's current CMakeLists.txt build messes up MACOSX_RPATH and cannot build the shared library, so this CMakeLists.txt tries to compensate for that by allowing to link the shared ZMQPP library with the static ZMQ lib. So far it seems to work for me, but it needs to be tested.
• IS_TRAVIS_CI_BUILD is On by default, because _sending_large_messagesstring test takes too long to comfortably use ctest.
• Since the client has bugs (typos) and wont compile, its disabled by default.
• Generally, ZMQPP is used as a lib for other projects, so it makes sense to turn off building the tests by default. Need more feedback on this.

[xaqq]

Hello, I agree having a CMake build system is a nice addition. However, I pulled your branch but cannot manage to build through CMake.

Here is the log:

-- The C compiler identification is GNU 4.9.1 -- The CXX compiler identification is GNU 4.9.1 -- Check for working C compiler: /usr/bin/cc -- Check for working C compiler: /usr/bin/cc -- works -- Detecting C compiler ABI info -- Detecting C compiler ABI info - done -- Check for working CXX compiler: /usr/bin/c++ -- Check for working CXX compiler: /usr/bin/c++ -- works -- Detecting CXX compiler ABI info -- Detecting CXX compiler ABI info - done -- Configuring done CMake Error at CMakeLists.txt:102 (add_library): Objects of target "zmqpp_objects" referenced but no such target exists.

CMake Error: CMake can not determine linker language for target: zmqpp CMake Error: Cannot determine link language for target "zmqpp". -- Generating done -- Build files have been written to: /tmp/zmqpp/build

I am running Debian. (cmake version 3.0.2)

[gyulalaszlo]

Hi!

Sorry, my bad, messed up the merge squash. Should be fixed now.

[xaqq]

Hi,

This effectively fixes some errors, but I cannot build tests (or examples). The include directories are wrong when building tests/examples project ("zmqpp/context.hpp" can't be found).

adding ${CMAKE_CURRENT_SOURCE_DIR}/src in a general include_directories() seems to fix it. I'm not very proficient at CMake so not sure about how good this is.

Can you build test w/o problem?

[gyulalaszlo]

Hi!

My bad again. Yes, to build the tests (or the client or the example) that include_directories is needed.

I also could not test building or using the shared library with shared libzmq.

ps: thank you for your patience, and sorry for this amateurishness, here is the reason it built on my system:

• I used zmqpp as a git submodule in another project and used a custom CMake file to build it then copy the headers over to a common include dir for vendor headers (before the install step)
• This CMakeLists.txt file was then extracted to be built as an ExternalProject, and that is the CMakeLists.txt I committed
• To test it, I simply built the ZMQPP CMake project in another directory separate directory, but I used the zmq lib and includes from the original projects build directory.
• This effectively pulled all the zmqpp headers, which were in the common vendor include directory.
• So everything compiled, and I somehow got rid of the include_directories(src) part...

[xaqq]

Hey,

No problem, thank you for your PR and CMake support.