c++ - 如何更改 MSVC++ 的 std::tuple 支持的模板参数的数量？

Question

MSVC++ 尚不支持可变参数模板，因此其标准库通过使用宏为 std::tuple 等类“伪造”这些模板。我最近尝试用 VC11 beta 编译我的一个项目，并得到了这个来展示它:

gtest\gtest.h(9735): error C2977: 'std::tuple' : too many template arguments
c:\program files (x86)\microsoft visual studio 11.0\vc\include\utility(72) : see declaration of 'std::tuple'
gtest\gtest.h(9743): error C2977: 'std::tuple' : too many template arguments
gtest\gtest.h(14568): error C2977: 'std::tuple' : too many template arguments
gtest\gtest.h(14568): error C3203: 'tuple' : unspecialized class template can't be used as a template argument for template parameter 'T', expected a real type
gtest\gtest.h(14568): error C2955: 'std::tuple' : use of class template requires template argument list
gtest\gtest.h(14568): error C2955: 'testing::internal::ParamGeneratorInterface' : use of class template requires template argument list
c:\users\billy\documents\visual studio 2010\projects\instalog\logtests\gtest\gtest.h(10076) : see declaration of 'testing::internal::ParamGeneratorInterface'
gtest\gtest.h(14570): error C2977: 'std::tuple' : too many template arguments
gtest\gtest.h(14581): error C3203: 'tuple' : unspecialized class template can't be used as a template argument for template parameter 'T', expected a real type
gtest\gtest.h(14581): error C2955: 'std::tuple' : use of class template requires template argument list
gtest\gtest.h(14586): error C3203: 'tuple' : unspecialized class template can't be used as a template argument for template parameter 'T', expected a real type
gtest\gtest.h(14586): error C2955: 'std::tuple' : use of class template requires template argument list
gtest\gtest.h(14593): error C3203: 'tuple' : unspecialized class template can't be used as a template argument for template parameter 'T', expected a real type
c:\users\billy\documents\visual studio 2010\projects\instalog\logtests\gtest\gtest.h(14593) : see reference to class template instantiation 'testing::internal::CartesianProductGenerator9<T1,T2,T3,T4,T5,T6,T7,T8,T9>::Iterator' being compiled
gtest\gtest.h(14593): error C2955: 'std::tuple' : use of class template requires template argument list
gtest\gtest.h(14593): error C2955: 'testing::internal::ParamIteratorInterface' : use of class template requires template argument list
c:\users\billy\documents\visual studio 2010\projects\instalog\logtests\gtest\gtest.h(10003) : see declaration of 'testing::internal::ParamIteratorInterface'
gtest\gtest.h(14595): error C3203: 'tuple' : unspecialized class template can't be used as a template argument for template parameter 'T', expected a real type
gtest\gtest.h(14595): error C2955: 'std::tuple' : use of class template requires template argument list
gtest\gtest.h(14628): error C3203: 'tuple' : unspecialized class template can't be used as a template argument for template parameter 'T', expected a real type
gtest\gtest.h(14628): error C2955: 'std::tuple' : use of class template requires template argument list
gtest\gtest.h(14670): error C3203: 'tuple' : unspecialized class template can't be used as a template argument for template parameter 'T', expected a real type
gtest\gtest.h(14670): error C2955: 'std::tuple' : use of class template requires template argument list
gtest\gtest.h(14674): error C3203: 'tuple' : unspecialized class template can't be used as a template argument for template parameter 'T', expected a real type
gtest\gtest.h(14674): error C2955: 'std::tuple' : use of class template requires template argument list
gtest\gtest.h(14755): error C3203: 'tuple' : unspecialized class template can't be used as a template argument for template parameter 'T', expected a real type
gtest\gtest.h(14755): error C2955: 'std::tuple' : use of class template requires template argument list
gtest\gtest.h(14807): error C2977: 'std::tuple' : too many template arguments
gtest\gtest.h(14807): error C3203: 'tuple' : unspecialized class template can't be used as a template argument for template parameter 'T', expected a real type
gtest\gtest.h(14807): error C2955: 'std::tuple' : use of class template requires template argument list
gtest\gtest.h(14807): error C2955: 'testing::internal::ParamGeneratorInterface' : use of class template requires template argument list
gtest\gtest.h(14809): error C2977: 'std::tuple' : too many template arguments
gtest\gtest.h(14821): error C3203: 'tuple' : unspecialized class template can't be used as a template argument for template parameter 'T', expected a real type
gtest\gtest.h(14821): error C2955: 'std::tuple' : use of class template requires template argument list
gtest\gtest.h(14826): error C3203: 'tuple' : unspecialized class template can't be used as a template argument for template parameter 'T', expected a real type
gtest\gtest.h(14826): error C2955: 'std::tuple' : use of class template requires template argument list
gtest\gtest.h(14833): error C3203: 'tuple' : unspecialized class template can't be used as a template argument for template parameter 'T', expected a real type
c:\users\billy\documents\visual studio 2010\projects\instalog\logtests\gtest\gtest.h(14833) : see reference to class template instantiation 'testing::internal::CartesianProductGenerator10<T1,T2,T3,T4,T5,T6,T7,T8,T9,T10>::Iterator' being compiled
gtest\gtest.h(14833): error C2955: 'std::tuple' : use of class template requires template argument list
gtest\gtest.h(14833): error C2955: 'testing::internal::ParamIteratorInterface' : use of class template requires template argument list
gtest\gtest.h(14835): error C3203: 'tuple' : unspecialized class template can't be used as a template argument for template parameter 'T', expected a real type
gtest\gtest.h(14835): error C2955: 'std::tuple' : use of class template requires template argument list
gtest\gtest.h(14871): error C3203: 'tuple' : unspecialized class template can't be used as a template argument for template parameter 'T', expected a real type
gtest\gtest.h(14871): error C2955: 'std::tuple' : use of class template requires template argument list
gtest\gtest.h(14917): error C3203: 'tuple' : unspecialized class template can't be used as a template argument for template parameter 'T', expected a real type
gtest\gtest.h(14917): error C2955: 'std::tuple' : use of class template requires template argument list
gtest\gtest.h(14921): error C3203: 'tuple' : unspecialized class template can't be used as a template argument for template parameter 'T', expected a real type
gtest\gtest.h(14921): error C2955: 'std::tuple' : use of class template requires template argument list
gtest\gtest.h(15007): error C3203: 'tuple' : unspecialized class template can't be used as a template argument for template parameter 'T', expected a real type
gtest\gtest.h(15007): error C2955: 'std::tuple' : use of class template requires template argument list
gtest\gtest.h(15289): error C2977: 'std::tuple' : too many template arguments
gtest\gtest.h(15289): error C3203: 'tuple' : unspecialized class template can't be used as a template argument for template parameter 'T', expected a real type
gtest\gtest.h(15289): error C2955: 'std::tuple' : use of class template requires template argument list
gtest\gtest.h(15333): error C2977: 'std::tuple' : too many template arguments
gtest\gtest.h(15333): error C3203: 'tuple' : unspecialized class template can't be used as a template argument for template parameter 'T', expected a real type
gtest\gtest.h(15333): error C2955: 'std::tuple' : use of class template requires template argument list

我听说有一个 #define 可以在某处设置以更改此设置，但我(对我来说)记不起它是什么了。这是什么？

Answer 1

您可以将 _VARIADIC_MAX 定义为 5 到 10(含)之间的任何值。

这个以及有关 Visual C++ 11 的许多其他有趣的事实，可以在 MSDN 文章“C++11 Features (Modern C++)”中找到。这个特定的宏在标题为“Faux variadics”的部分中进行了讨论。