C ++哈希弃用警告 [英] C++ Hash Deprecation Warning

问题描述

我一般对C ++和编程都不熟悉，目前正在研究Bjarne Stroustrup的《编程：使用C ++的原理和实践》。我一直在收到以下错误消息

I am very new to C++ and programming in general and am currently working through Bjarne Stroustrup's Programming: Principles and Practices using C++. I'm consistently receiving the error below

严重性代码说明项目文件行错误C2338已弃用
，并将被删除。请用 。您可以
定义_SILENCE_STDEXT_HASH_DEPRECATION_WARNINGS来确认您已收到此警告
。

Severity Code Description Project File Line Error C2338 is deprecated and will be REMOVED. Please use . You can define _SILENCE_STDEXT_HASH_DEPRECATION_WARNINGS to acknowledge that you have received this warning.

我知道头文件std_lib_facilities.h使用某种不推荐使用的功能，但是有办法绕过此功能吗？似乎要我定义 _SILENCE_STDEXT_HASH_DEPRECATION_WARNINGS，但是我不确定该怎么做。

I understand that the header file std_lib_facilities.h using some sort of deprecated function, but is there a way to bypass this? It looks like it wants me to define "_SILENCE_STDEXT_HASH_DEPRECATION_WARNINGS" but I'm unsure of how to do that. Any help would be appreciated!!

推荐答案

警告不是关于某些功能的问题，而是整个 stdext 。而且它不仅是手工波浪形的，最终会被弃用，最终会被弃用：2015年不提供。

The warning isn't about "some function" - it's about the whole of stdext. And it's not just hand-wavy, to be discontinued eventually, deprecated: it doesn't ship with 2015.

00年代初期的工作即将修订C ++标准；包括Microsoft在内的不同编译器供应商将建议和原型一起提交给委员会。因此，可以对其进行测试和评估，Microsoft将其扩展建议的实现放入 stdext 。

During the early 00's work was afoot to revise the C++ standard; different compiler vendors, Microsoft included, put proposals before the committee along with prototypes. So they could be tested and evaluated, Microsoft placed implementations of their proposed extensions in stdext.

最终，委员会选择了他们将要纳入该修订版的内容，并发布了技术报告（ TR1）。预期在2009年底之前完成，这被称为 C ++ 0x，编译器供应商开始在 tr1 命名空间中实现这些功能。最终在2011年，该标准得以最终确定，我们将C ++ 11及其所有内容全部归还到它们所属的 std 中。

Eventually the committee chose what they were going to incorporate in that revision and released a Technical Report ("TR1"). Anticipating completion before the end of 2009, this was referred to as "C++0x", and compiler vendors began implementing these features in the tr1 namespace. Finally in 2011 the standard was finalized and we got "C++11" with all its bit and pieces back in std where they belong.

根据Microsoft的建议，容器将为 std :: hash_map ，但是C ++委员会选择使用术语 unordered_map 。 std :: map 是一个有序的容器， stdext :: hash_map 尽管有名字，却不是。

According to Microsoft's proposal, the container would be std::hash_map, but the C++ committee chose to use the term unordered_map. std::map is an ordered container, stdext::hash_map, despite the name, is not.

Microsoft的编译器在完成对C ++ 11的完整支持方面一直是最慢的，而标准委员会此后已经完成了第二个版本（C ++ 14），并正在研究第三个版本。 （C ++ 17）。微软即将在VS2015中完成C ++ 11和大部分C ++ 14，但有一些明显的例外显然是VS编译器的主要问题（特别是constexpr和模板变量）。

Microsoft's compiler has been the slowest at getting full C++11 support finished, and the standards committee has since finished a second variation (C++14) and is working on a third (C++17). Microsoft is just-about finishing C++11 in VS2015 and a big chunk of C++14, with a few significant exceptions that are apparently going to be a major problem for the VS compiler (esp constexpr and template variables).

1. Visual Studio 2015不提供 stdext -它是消失。这不是很好，它最终可能会消失的情况之一。

1. Visual Studio 2015 does not provide stdext - it's gone. This is not one of those "well, it may eventually go away" cases.

stdext 是特定于Microsoft编译器系列的，因此使用 stdext :: 编写代码是不可移植的： http://ideone.com/x8GsKY

stdext is specific to the Microsoft family of compilers, so writing code using stdext:: anything is not portable: http://ideone.com/x8GsKY

您想要的功能是 std :: unordered_map ，则应使用该功能。

The standardized version of the feature you're wanting is std::unordered_map, you should use that. It's essentially the same thing.

stdext :: hash_map 中有未解决的错误。

如果您确实需要使用 stdext :: hash_map ，请静默通过添加

If you really have to use stdext::hash_map, silence the warning by adding

#define _SILENCE_STDEXT_HASH_DEPRECATION_WARNINGS

$ b警告
$ b

位于 stdafx.h 的顶部，我认为您的项目已经存在，或者位于＃之前的头文件中＃包括< stdext /...& gt; ，或在解决方案资源管理器中：

at the top of the stdafx.h I assume your project has, or in your header files before you #include <stdext/...>, or in the solution explorer:

• 右键单击您的解决方案资源管理器中的项目条目，


• 选择属性，


• 选择配置：所有配置，


• 展开 C / C ++ 树条目，


• 选择预处理程序，


• 预处理程序定义可能会说<不同的选项>


• 在预处理程序定义条目的开头添加 _SILE NCE_STDEXT_HASH_DEPRECATION_WARNINGS = 1; ，因此它读取 _SILENCE_STDEXT_HASH_DEPRECATION_WARNINGS = 1;<不同的选项> 。
  （或最初出现在; 之后的任何内容）

• Right click on your project's entry in solution explorer,
• Select Properties,
• Select Configuration: All Configurations,
• Expand the C/C++ tree entry,
• Select Preprocessor,
• The "Preprocessor Definitions" will probably say <different options>
• At the beginning of the "Preprocessor Definitions" entry add _SILENCE_STDEXT_HASH_DEPRECATION_WARNINGS=1; so it reads _SILENCE_STDEXT_HASH_DEPRECATION_WARNINGS=1;<different options>. (or whatever was there originally should follow the ;)

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