C2977：'std :: tuple'：太多模板参数（MSVC11） [英] C2977: 'std::tuple' : too many template arguments (MSVC11)

问题描述

我尝试使用Visual C ++ 11构建googletest，但以下代码导致错误

I'm trying to build googletest with Visual C++ 11, but following code causes an error

template <typename T1, typename T2, typename T3, typename T4, typename T5,
          typename T6, typename T7, typename T8, typename T9>
void PrintTo(const ::std::tr1::tuple<T1, T2, T3, T4, T5, T6, T7, T8, T9>& t, // <-- error C2977
             ::std::ostream* os) {
  PrintTupleTo(t, os);
}

这是一个错误文本：

f:\gtest-1.6.0\include\gtest\gtest-printers.h(550): 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'

并且实用程序的第72行 -file：

template<class = _Nil, _MAX_CLASS_LIST>
   class tuple; // Line 72

std :: tuple 以及如何修复它？

What is the problem with std::tuple and how to fix it?

（BTW：我尝试不成功更改 std :: tr1 :: tuple 到 std :: tuple ）

(BTW: I'm tried unsuccessfully to change std::tr1::tuple to std::tuple )

推荐答案

请在 msdn博客中查看此条目。 VC ++ 11不支持可变参数模板。他们有一些他们称之为人为变化的东西。向下滚动，你会看到一个关于假的可变参数的段落，涉及元组。在该段中，他们说默认的最大参数数为5.您可以将其增加到10：

Check out this entry in the msdn blog. VC++11 doesn't have support for variadic templates. They have something they call faux variadics. Scroll down and you will see a paragraph on Faux variadics that talks about tuples. On that paragraph they say the default maximum number of parameters is 5. You can increase it to 10:

您可以定义_VARIADIC_MAX介于5和10之间（默认为5）。增加它将使编译器消耗更多的内存，并且可能需要您使用/ Zm选项为PCHes预留更多空间。

You can define _VARIADIC_MAX project-wide between 5 and 10 inclusive (it defaults to 5). Increasing it will make the compiler consume more memory, and may require you to use the /Zm option to reserve more space for PCHes.

他们说他们有一个修复传入，再次使默认10。

They say they have a fix incoming to make the default 10 again.

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