Build Failure with AppleClang 10.0.0

[ankane]

Hi, thanks for open sourcing this library.

When building the latest two versions (2020.06.29 and 2020.06.15 - haven't tried others) on MacOS 13 (High Sierra), it fails with:

[ 56%] Building CXX object CMakeFiles/TokenBindingConstructorTest.dir/test/CMakeTestMain.cpp.o
/usr/local/Homebrew/Library/Homebrew/shims/mac/super/clang++  -DBOOST_ALL_NO_LIB -DBOOST_CONTEXT_DYN_LINK -DBOOST_FILESYSTEM_DYN_LINK -DBOOST_PROGRAM_OPTIONS_DYN_LINK -DBOOST_REGEX_DYN_LINK -DBOOST_SYSTEM_DYN_LINK -DBOOST_THREAD_DYN_LINK -DFMT_LOCALE -DFMT_SHARED -DGFLAGS_IS_A_DLL=0 -DTokenBindingConstructorTest_EXPORTS -I/tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/build/gtest/src/gtest/googlemock/include -I/tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/build/gtest/src/gtest/googletest/include -I/tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00  -DNDEBUG -fPIE   -std=c++14 -Wno-inconsistent-missing-override -std=gnu++14 -o CMakeFiles/TokenBindingConstructorTest.dir/test/CMakeTestMain.cpp.o -c /tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/test/CMakeTestMain.cpp
In file included from /tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/server/test/AsyncFizzServerTest.cpp:12:
In file included from /tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/server/AsyncFizzServer.h:13:
In file included from /tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/server/FizzServer.h:13:
In file included from /tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/server/ServerProtocol.h:17:
In file included from /tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/server/Actions.h:11:
/tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/protocol/Actions.h:106:46: error: no matching constructor for initialization of 'std::__1::array<fizz::server::Action, 0>::value_type' (aka 'fizz::server::Action')
  Arr arr{{std::forward<ActionType&&>(act)...}};
                                             ^
/tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/server/Actions.h:64:17: note: in instantiation of function template specialization 'fizz::detail::addAction<folly::small_vector<fizz::server::Action, 4, void, void, void>>' requested here
  fizz::detail::addAction(acts, std::forward<Args>(act)...);
                ^
/tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/server/test/AsyncFizzServerTest.cpp:319:23: note: in instantiation of function template specialization 'fizz::server::detail::actions<>' requested here
  p1.setValue(detail::actions());
                      ^
/tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/server/Actions.h:54:27: note: candidate constructor not viable: requires single argument 'x', but no arguments were provided
FIZZ_DECLARE_VARIANT_TYPE(Action, FIZZ_SERVER_ACTIONS)
                          ^
/tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/server/Actions.h:54:27: note: candidate constructor not viable: requires single argument 'x', but no arguments were provided
/tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/server/Actions.h:54:27: note: candidate constructor not viable: requires single argument 'x', but no arguments were provided
/tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/server/Actions.h:54:27: note: candidate constructor not viable: requires single argument 'x', but no arguments were provided
/tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/server/Actions.h:54:27: note: candidate constructor not viable: requires single argument 'x', but no arguments were provided
/tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/server/Actions.h:54:27: note: candidate constructor not viable: requires single argument 'x', but no arguments were provided
/tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/server/Actions.h:54:27: note: candidate constructor not viable: requires single argument 'x', but no arguments were provided
/tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/server/Actions.h:54:27: note: candidate constructor not viable: requires single argument 'x', but no arguments were provided
/tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/server/Actions.h:54:27: note: candidate constructor not viable: requires single argument 'x', but no arguments were provided
/tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/server/Actions.h:54:27: note: candidate constructor not viable: requires single argument 'x', but no arguments were provided
/tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/server/Actions.h:54:27: note: candidate constructor not viable: requires single argument 'other', but no arguments were provided
/tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/server/Actions.h:54:27: note: candidate constructor (the implicit copy constructor) not viable: requires 1 argument, but 0 were provided
/tmp/fizz-20200630-40082-z2sk48/fizz-2020.06.29.00/fizz/protocol/Actions.h:106:46: note: in implicit initialization of array element 0 with omitted initializer
  Arr arr{{std::forward<ActionType&&>(act)...}};

The CXX compiler identification is AppleClang 10.0.0.10001145.

[ankane]

With the release of macOS 11, I'm not sure macOS 10.13 is supported anymore, so will close this out.