c++11:枚举类型(enum)的前向声明(forward declaration) 在C++11之前,C++标准是不支持枚举类型的前向声明的。我说出这个结论,肯定有用msvc的童鞋不愿意了:口胡,MSVC明明就可以对枚举类型前向声明,下面这样的前向声明在MSVC下好好的,没有任何问题。 代码语言:javascript 复制 enumE; 是哦,你说的对,MSVC下上面的写...
使用-features=extensions时,编译器允许对enum类型和变量进行前向声明。此外,编译器允许声明不完整enum类型的变量。编译器总是假定不完整enum类型的大小和范围与当前平台上的int类型相同。 以下是两行无效代码示例,如果使用-features=extensions选项,可对其进行编译。 enum E; // invalid: forward declaration of enum n...
More details can be found in [0], but it comes down to C++ supporting enum forward declaration only with explicitly specified backing type: enum bpf_stats_type: int; In C (and I believe it's a GCC extension also), such forward declaration is simply: enum bpf_stats_type; Furt...
当我们在C++程序中声明一个枚举类型时,有时会碰到类似"Enum does not name a type"的错误消息。这种错误通常是因为调用枚举类型时,编译器还没有识别出它所引用的类型。这个问题很容易通过添加一个前置声明来解决,例如: //前置声明(forward declaration)枚举类型 enum MyEnum; //定义结构体 struct MyStruct{ MyEn...
代码下载地址 https://github.com/xueweiguo/OOThinking/tree/master/20180603%20ForwardDeclarationOfEnum/ForwardDeclarationOfEnum 觉得本文有帮助?请分享给更多人。 阅读更多更新文章,请扫描下面二维码,关注微信公众号【面向对象思考】
// forward declarationenumclassStatus;// use of fwd-declared enumvoidcontinueProcessing(Statuss); 2) 潜在类型 enum class的潜在类型 (underlying type),缺省为 int 型,当然也可自定义潜在类型。无论哪种方式,编译器都会预先知道枚举成员的大小 // underlying type is intenumclassStatus;// underlying type ...
3. the underlying type of an enum cannot be specified, causing confusion,compatibility problems, and makes forward declaration impossible. The new enums are "enum class" because they combine aspects of traditional enumerations (names values) with aspects of classes (scoped members and absense of ...
// forward declaration enum class Status; // use of fwd-declared enum void continueProcessing(Status s); 1. 2. 3. 4. 5. 2) 潜在类型 enum class 的潜在类型 (underlying type),缺省为 int 型,当然也可自定义潜在类型。无论哪种方式,编译器都会预先知道枚举成员的大小 // underlying type is int...
Some further information about the new features I'm attempting to use: Strongly typed enums:http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2347.pdf Forward declaration of enums:http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2764.pdf...
the underlying type of anenumcannot be specified, causing confusion, compatibility problems, and makes forward declaration impossible. The new enums are "enum class" because they combine aspects of traditional enumerations (names values) with aspects of classes (scoped members and absence of conversio...