Missing #include's for in_place_factory when compiling for CUDA with clang

Start with boost/optional/detail/optional_factory_support.hpp and boost/optional/optional.hpp, then reproduce the reported failure using the CUDA clang snippet on Compiler Explorer. Check the include dependencies for in_place_factory and typed_in_place_factory; done means the same boost/format.hpp include compiles without callers adding those utility headers manually.

I'm not sure if this is an optional or Boost.Format issue, but I suspect this belongs here.

The issue is that some optional methods use in_place_factory as an argument to is_base_of which absolutely requires a complete type as argument, but so far as I can see in_place_factory is only ever forward declared.

When compiling for CUDA with clang this leads to:

In file included from <source>:14:
In file included from /opt/compiler-explorer/libs/boost_1_77_0/boost/format.hpp:38:
In file included from /opt/compiler-explorer/libs/boost_1_77_0/boost/format/internals.hpp:21:
In file included from /opt/compiler-explorer/libs/boost_1_77_0/boost/optional.hpp:15:
In file included from /opt/compiler-explorer/libs/boost_1_77_0/boost/optional/optional.hpp:43:
In file included from /opt/compiler-explorer/libs/boost_1_77_0/boost/type_traits/is_base_of.hpp:12:
/opt/compiler-explorer/libs/boost_1_77_0/boost/type_traits/is_base_and_derived.hpp:142:25: error: invalid application of 'sizeof' to an incomplete type 'boost::in_place_factory_base'
    BOOST_STATIC_ASSERT(sizeof(B) != 0);
                        ^~~~~~~~~
/opt/compiler-explorer/libs/boost_1_77_0/boost/static_assert.hpp:70:55: note: expanded from macro 'BOOST_STATIC_ASSERT'
#     define BOOST_STATIC_ASSERT( ... ) static_assert(__VA_ARGS__, #__VA_ARGS__)
                                                      ^~~~~~~~~~~
/opt/compiler-explorer/libs/boost_1_77_0/boost/type_traits/is_base_and_derived.hpp:217:41: note: in instantiation of template class 'boost::detail::is_base_and_derived_impl2<boost::in_place_factory_base, std::locale>' requested here
    BOOST_STATIC_CONSTANT(bool, value = bound_type::value);
                                        ^
/opt/compiler-explorer/libs/boost_1_77_0/boost/type_traits/is_base_of.hpp:25:31: note: in instantiation of template class 'boost::detail::is_base_and_derived_impl<boost::in_place_factory_base, std::locale>' requested here
            (::boost::detail::is_base_and_derived_impl<ncvB,ncvD>::value) ||
                              ^
/opt/compiler-explorer/libs/boost_1_77_0/boost/type_traits/is_base_of.hpp:31:58: note: in instantiation of template class 'boost::detail::is_base_of_imp<boost::in_place_factory_base, std::locale>' requested here
      : public integral_constant<bool, (::boost::detail::is_base_of_imp<Base, Derived>::value)> {};
                                                         ^
/opt/compiler-explorer/libs/boost_1_77_0/boost/optional/optional.hpp:794:32: note: in instantiation of template class 'boost::is_base_of<boost::in_place_factory_base, std::locale>' requested here
  : boost::conditional< boost::is_base_of<boost::in_place_factory_base, BOOST_DEDUCED_TYPENAME boost::decay<U>::type>::value
                               ^
/opt/compiler-explorer/libs/boost_1_77_0/boost/optional/optional.hpp:823:25: note: in instantiation of template class 'boost::optional_detail::is_convertible_to_T_or_factory<std::locale, const std::locale &>' requested here
  : boost::conditional< is_convertible_to_T_or_factory<T, U>::value
                        ^
/opt/compiler-explorer/libs/boost_1_77_0/boost/core/enable_if.hpp:41:41: note: in instantiation of template class 'boost::optional_detail::is_optional_val_init_candidate<std::locale, const std::locale &, false>' requested here
  struct enable_if : public enable_if_c<Cond::value, T> {};
                                        ^
/opt/compiler-explorer/libs/boost_1_77_0/boost/optional/optional.hpp:951:53: note: in instantiation of template class 'boost::enable_if<boost::optional_detail::is_optional_val_init_candidate<std::locale, const std::locale &, false>, bool>' requested here
                      BOOST_DEDUCED_TYPENAME boost::enable_if< optional_detail::is_optional_val_init_candidate<T, Expr>, bool>::type = true
                                                    ^
/opt/compiler-explorer/libs/boost_1_77_0/boost/format/format_implementation.hpp:40:44: note: while substituting deduced template arguments into function template 'optional' [with Expr = const std::locale &]
          exceptions_(io::all_error_bits), loc_(loc)
                                           ^
/opt/compiler-explorer/libs/boost_1_77_0/boost/optional/detail/optional_factory_support.hpp:32:9: note: forward declaration of 'boost::in_place_factory_base'
  class in_place_factory_base ;

You can see the issue here: https://godbolt.org/#g:!((g:!((g:!((h:codeEditor,i:(filename:'1',fontScale:14,fontUsePx:'0',j:1,lang:cuda,selection:(endColumn:23,endLineNumber:9,positionColumn:23,positionLineNumber:9,selectionStartColumn:23,selectionStartLineNumber:9,startColumn:23,startLineNumber:9),source:'%23include+%3Cboost/config.hpp%3E%0A//%0A//+These+%23undefs+reflect+the+current+state+of+Boost.Config+develop+compared+to+1.77:%0A//%0A%23undef+BOOST_NO_CXX11_VARIADIC_TEMPLATES%0A%23undef+BOOST_NO_VARIADIC_TEMPLATES%0A//%0A//+These+includes+are+required+to+make+this+compile,%0A//+uncomment+to+remove+the+errors:%0A//%0A//%23include+%3Cboost/utility/in_place_factory.hpp%3E%0A//%23include+%3Cboost/utility/typed_in_place_factory.hpp%3E%0A%0A%23include+%3Cboost/format.hpp%3E%0A'),l:'5',n:'0',o:'CUDA+C%2B%2B+source+%231',t:'0')),k:63.22701688555347,l:'4',n:'0',o:'',s:0,t:'0'),(g:!((g:!((h:compiler,i:(compiler:cuclang1100,filters:(b:'0',binary:'1',commentOnly:'0',demangle:'0',directives:'0',execute:'1',intel:'0',libraryCode:'0',trim:'1'),flagsViewOpen:'1',fontScale:14,fontUsePx:'0',j:1,lang:cuda,libs:!(),options:'-std%3Dc%2B%2B14+-O3+-I/opt/compiler-explorer/libs/boost_1_77_0/',selection:(endColumn:1,endLineNumber:1,positionColumn:1,positionLineNumber:1,selectionStartColumn:1,selectionStartLineNumber:1,startColumn:1,startLineNumber:1),source:1,tree:'1'),l:'5',n:'0',o:'clang+11.0.0+sm_75+CUDA-10.2+(CUDA+C%2B%2B,+Editor+%231,+Compiler+%231)',t:'0')),header:(),k:43.667751209994,l:'4',m:50,n:'0',o:'',s:0,t:'0'),(g:!((h:output,i:(compiler:1,editor:1,fontScale:12,fontUsePx:'0',wrap:'1'),l:'5',n:'0',o:'Output+of+clang+11.0.0+sm_75+CUDA-10.2+(Compiler+%231)',t:'0')),header:(),l:'4',m:50,n:'0',o:'',s:0,t:'0')),k:36.77298311444653,l:'3',n:'0',o:'',t:'0')),l:'2',m:100,n:'0',o:'',t:'0')),version:4

Adding

#include <boost/utility/in_place_factory.hpp>
#include <boost/utility/typed_in_place_factory.hpp>

Before including optional.hpp fixes the issue.