是否允许元组的元组? [英] Are tuples of tuples allowed?

问题描述

我目前正在使用具有许多模板的类，并且能够构建元组的元组将使其变得更加简单

I'm currently working on a class with a lot of templates and being able to build tuples of tuples would make it a lot easier

但是我在MSVC ++ 2010中尝试了以下简单代码:

But I tried this simple code in MSVC++ 2010:

#include <tuple>

void main() {
     auto x = std::make_tuple(std::make_tuple(5, true));
}

我得到一个编译错误.如果我不使用std::make_tuple而是直接使用std::tuple的构造函数，则会发生相同的问题.

And I get a compilation error. The same problem happens if I don't use std::make_tuple but directly std::tuple's constructor.

是MSVC的错误还是标准不允许的元组?

Is it a bug of MSVC or are tuples of tuples not allowed by the standard?

推荐答案

更多数据点:

• 如果我们使用std::tr1::tuple并明确声明类型而不是使用auto，则Visual C ++ 2008会编译代码而不会出现错误.尝试使用Visual C ++ 2010编译相同的代码会导致您看到错误.

• If we use std::tr1::tuple and explicitly state the type instead of using auto, then Visual C++ 2008 compiles the code without error. Trying to compile that same code with Visual C++ 2010 results in the error you are seeing.

如果我们使用boost::tuple显式声明类型而不是使用auto，则Visual C ++ 2008和Visual C ++ 2010都可以正确地编译代码.

If we use boost::tuple an explicitly state the type instead of using auto, then Visual C++ 2008 and Visual C++ 2010 both compile the code without error.

它看起来可能是实现错误.

It looks like it is probably an implementation bug.

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