Compilation error in Windows (VS 2017)

[Danl2620]

Building on Windows I get this compilation error:

afsm\include\afsm/definition.hpp(231): error C2977: 'afsm::def::traits::inner_states_definitions': too many template arguments
afsm\include\afsm/detail/def_traits.hpp(151): note: see declaration of 'afsm::def::traits::inner_states_definitions'
afsm\include\afsm/definition.hpp(254): note: see reference to class template instantiation 'afsm::def::state_machine_def<T,Tags...>' being compiled
afsm\include\afsm/definition.hpp(232): error C2143: syntax error: missing ';' before '>'
afsm\include\afsm/definition.hpp(232): error C2059: syntax error: '>'
afsm\include\afsm/definition.hpp(232): error C2238: unexpected token(s) preceding ';'

[zmij]

Could you please be a little more specific? What are you building? Just the library? Which git branch are you using?

Unfortunately I don't have a Windows machine, so I've never tried to compile the library with VS.

[Danl2620]

I'm including afsm/fsm.hpp into a .cpp file in an Unreal project which is building on windows using VS 2017. My branch is develop. We're also building on macOS using clang and it does not have this compile error...

[zmij]

The library requires my other library https://github.com/zmij/metapushkin and in CMake environment it is downloaded as an external project.
Can you put the metapushkin includes into your include search paths and give it another try?

[Jedzia]

I had problems with these ExternalProjectX shenanigans, too

In a folder with CMakeLists.txt
and afsm + metapushkin as submodules, declare:

add_library(afsm INTERFACE)
target_include_directories(afsm INTERFACE "${CMAKE_CURRENT_SOURCE_DIR}/metapushkin/include;${CMAKE_CURRENT_SOURCE_DIR}/afsm/include")

add_library(afsm::afsm ALIAS afsm)

that enables you to

target_link_libraries(YOUR_TARGET PRIVATE afsm::afsm)

when just using the headers

[Skoparov]

I'm not sure if it's still relevant, but the issue seems to be that msvc doesn't handle specializing template classes with template typedefs all that well. Simply changing state to state_def in inner_states_definitions<state<StateMachine, Tags...>> fixed the problem for me.