包含带有 Unreal 5 的 Boost 1.79.0 Bimap 时的编译错误

Question

一年多来，我一直在使用 Boost 的 Bimap 作为库存系统的基础。

typedef boost::bimap<boost::bimaps::set_of<uint32>,
    boost::bimaps::multiset_of<uint32>,
    boost::bimaps::with_info<FItemDetails>> InventoryBimap;

不过，在从 Unreal 4 更新到 Unreal 5 之后，我做了一些其他更改。我从 Boost 1.68.0 移到了 1.79.0。我从 C++17 转移到 C++20。

编辑：抱歉，我忘了包括我正在使用 Visual Studio 2022。

阻止我的游戏编译的一堆编译错误有两个来源：

1>H:\UnrealEngine\Engine\Source\ThirdParty\boost\boost-1_79_0\include\boost\core\pointer_traits.hpp(120): error C2988: unrecognizable template declaration/definition
1>H:\UnrealEngine\Engine\Source\ThirdParty\boost\boost-1_79_0\include\boost\core\pointer_traits.hpp(127): note: see reference to class template instantiation 'boost::detail::ptr_to_expr<T,E>' being compiled
1>H:\UnrealEngine\Engine\Source\ThirdParty\boost\boost-1_79_0\include\boost\core\pointer_traits.hpp(120): error C2059: syntax error: '<end Parse>'
1>H:\UnrealEngine\Engine\Source\ThirdParty\boost\boost-1_79_0\include\boost\core\pointer_traits.hpp(120): error C2334: unexpected token(s) preceding '{'; skipping apparent function body
1>H:\UnrealEngine\Engine\Source\ThirdParty\boost\boost-1_79_0\include\boost\core\pointer_traits.hpp(120): error C2988: unrecognizable template declaration/definition
1>H:\UnrealEngine\Engine\Source\ThirdParty\boost\boost-1_79_0\include\boost\core\pointer_traits.hpp(120): error C2059: syntax error: '->'
1>H:\UnrealEngine\Engine\Source\ThirdParty\boost\boost-1_79_0\include\boost\core\pointer_traits.hpp(120): error C2238: unexpected token(s) preceding ';'
1>H:\UnrealEngine\Engine\Source\ThirdParty\boost\boost-1_79_0\include\boost\core\pointer_traits.hpp(123): error C2988: unrecognizable template declaration/definition
1>H:\UnrealEngine\Engine\Source\ThirdParty\boost\boost-1_79_0\include\boost\core\pointer_traits.hpp(123): error C2059: syntax error: '<end Parse>'
1>H:\UnrealEngine\Engine\Source\ThirdParty\boost\boost-1_79_0\include\boost\core\pointer_traits.hpp(123): error C2334: unexpected token(s) preceding '{'; skipping apparent function body

然后：

1>H:\UnrealEngine\Engine\Source\ThirdParty\boost\boost-1_79_0\include\boost\core\allocator_access.hpp(397): error C2988: unrecognizable template declaration/definition
1>H:\UnrealEngine\Engine\Source\ThirdParty\boost\boost-1_79_0\include\boost\core\allocator_access.hpp(407): note: see reference to class template instantiation 'boost::detail::alloc_has_allocate<A>' being compiled
1>H:\UnrealEngine\Engine\Source\ThirdParty\boost\boost-1_79_0\include\boost\core\allocator_access.hpp(397): error C2059: syntax error: '<end Parse>'
1>H:\UnrealEngine\Engine\Source\ThirdParty\boost\boost-1_79_0\include\boost\core\allocator_access.hpp(397): error C2334: unexpected token(s) preceding '{'; skipping apparent function body
1>H:\UnrealEngine\Engine\Source\ThirdParty\boost\boost-1_79_0\include\boost\core\allocator_access.hpp(398): error C2988: unrecognizable template declaration/definition
1>H:\UnrealEngine\Engine\Source\ThirdParty\boost\boost-1_79_0\include\boost\core\allocator_access.hpp(398): error C2059: syntax error: '->'
1>H:\UnrealEngine\Engine\Source\ThirdParty\boost\boost-1_79_0\include\boost\core\allocator_access.hpp(400): error C2238: unexpected token(s) preceding ';'

对于 allocator_access.hpp 中的每个模板，都会重复第二个错误。

到目前为止，我发现的唯一短期修复方法是注释掉我项目中包含的所有 bimap。

我目前不确定如何进行，希望有人对可能发生的事情有所了解。

Answer 1

所以，我找到了答案。在这里分享一下，让大家知道：

在pointer_traits.hpp中，模板有两个作用：

        template<class O>
        static auto check(int)->result<decltype(O::pointer_to(source()))>;

        template<class>
        static char check(long);

我突然注意到了这个名字：“检查”。

“check”是一个虚幻宏名称，它强制虚幻引擎在调用时崩溃（除非附加了调试器）。因此，函数调用看着normal 被解释为调用 Unreal 的检查宏并导致编译失败。

所以我不得不在整个提升过程中将“检查”重命名为其他名称。这修复了编译错误，我的库存系统又开始工作了。

Answer 2

我也遇到过这个问题，PosoKhov 的解决方案是最快、最干净的。分叉 UE 存储库和修改宏很快就变得一团糟，因为它似乎也在插件中被引用。