什么是C ++ 11扩展[-Wc ++ 11-extensions] [英] What is a C++11 extension [-Wc++11-extensions]

问题描述

我需要一些帮助来了解发生此错误的位置：

I need some help understanding where this error is occurring:

警告：非静态数据成员的类内初始化是C ++ 11扩展[-Wc ++ 11-extensions]

warning: in-class initialization of non-static data member is a C++11 extension [-Wc++11-extensions]

这是它来自的代码部分：

This is the section of the code that it is coming from:

typedef struct Hand {
    bool straight = false;
    bool flush = false;
    bool four = false;
    bool three = false;
    int pairs = 0;
    } Hand;

推荐答案

这不是错误，是警告。它告诉您，仅允许初始化以C ++ 11标准（之所以称呼，因为它于2011年发布）开始的struct / class的非静态成员。在此之前，C ++ 98并没有正式允许您这样做（您猜想它是在1998年出版的）。长话短说，您的操作在2011年才成为合法的官方C ++。编译器的默认似乎是1998年的标准。

That's not an error, it's a warning. It tells you that you're only allowed to initialize non-static members of a struct / class starting with the C++11 standard (so called because it was published in 2011). Before that, you weren't officially allowed to by C++98 (published, you've guessed it, in 1998). Long story short, what you're doing has only become legal, official C++ in 2011. Your compiler's default seems to be the 1998 standard.

尝试使用<$ c进行编译$ c> -std = c ++ 11 作为命令行标志（假设您使用的是GCC或clang），警告应该消失了。如果您使用的是其他编译器，则还应该有一个标志（如果它足够新，可以实现C ++ 11）。

Try compiling with -std=c++11 as a command line flag (assuming you're using GCC or clang), and the warning should go away. If you're using a different compiler, there should be a flag for that as well (if it's recent enough to implement C++11).

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