Tests fail to build

[AlexanderAmelkin]

While developing a solution to #88 I encountered a problem with the tests. I can't build them.
Here is what I do:

CLI11 $ $ git status   
On branch master
Your branch is up-to-date with 'origin/master'.
nothing to commit, working directory clean
CLI11 $ $ git submodule update --init
Submodule 'extern/googletest' (git@github.com:google/googletest.git) registered for path 'extern/googletest'
Submodule 'extern/json' (git@github.com:nlohmann/json.git) registered for path 'extern/json'
Submodule 'extern/sanitizers' (git@github.com:arsenm/sanitizers-cmake) registered for path 'extern/sanitizers'
Submodule path 'extern/googletest': checked out 'ec44c6c1675c25b9827aacd08c02433cccde7780'
Submodule path 'extern/json': checked out 'db53bdac1926d1baebcb459b685dcd2e4608c355'
Submodule path 'extern/sanitizers': checked out '6947cff3a9c9305eb9c16135dd81da3feb4bf87f'
CLI11 $ mkdir build
CLI11 $ cd build
build $ cmake ..
-- The CXX compiler identification is GNU 8.1.0
-- 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
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- The C compiler identification is GNU 8.1.0
-- 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
-- Detecting C compile features
-- Detecting C compile features - done
-- Found PythonInterp: /usr/bin/python (found version "2.7.12") 
-- Looking for pthread.h
-- Looking for pthread.h - found
-- Looking for pthread_create
-- Looking for pthread_create - not found
-- Looking for pthread_create in pthreads
-- Looking for pthread_create in pthreads - not found
-- Looking for pthread_create in pthread
[- Looking for pthread_create in pthread - found
-- Found Threads: TRUE  
-- Boost version: 1.58.0
-- Configuring done
WARNING: Target "informational" requests linking to directory "/usr/include".  Targets may link only to libraries.  CMake is dropping the item.
-- Generating done
-- Build files have been written to: /home/spirit/src/community/CLI11/build
build $ make
Scanning dependencies of target gtest
[  1%] Building CXX object extern/googletest/googlemock/gtest/CMakeFiles/gtest.dir/src/gtest-all.cc.o
[  2%] Linking CXX static library libgtest.a
[  2%] Built target gtest
...
Scanning dependencies of target OptionalTest
[ 42%] Building CXX object tests/CMakeFiles/OptionalTest.dir/OptionalTest.cpp.o
...
/usr/include/boost/optional/optional.hpp:619:7: error: no matching function for call to 'boost::optional_detail::optional_base<int>::assign_value(std::__cxx11::basic_string<char>&, boost::optional_detail::optional_base<int>::is_reference_predicate)'
       assign_value(boost::forward<Expr>(expr), is_reference_predicate());
...
/usr/include/boost/optional/optional.hpp:608:7: error: cannot convert 'std::__cxx11::basic_string<char>' to 'boost::optional_detail::optional_base<int>::internal_type' {aka 'int'} in initialization
       new (m_storage.address()) internal_type(boost::forward<Expr>(expr)) ;

The full log is attached

[henryiii]

Testing this on a Boost docker with 1.59 and CMake 3.5:

WARNING: Target "informational" requests linking to directory "/usr/include/boost".  Targets may link only to libraries.  CMake is dropping the item.

Along with a different failure. I think that warning is telling; the link is not working properly. I bet your CMake version is a bit older, too?

I've fixed the error from CMake (obviously never ran it with a non-target version of FindBoost), but the actual error is troubling - lexical cast can't go from a string to a boost optional. Might need a newer version than 1.59.

[henryiii]

Boost 1.60 also fails with a similar error, Boost 1.61 works.

[henryiii]

Latest master should now work! It won't build the Boost Optional test because your Boost is too old, but everything else should build!