引用类型和文字类型

Question

我在标准中查找了 引用类型 的定义，但找不到任何内容。将 引用类型 天真解释为 int & 等对象的类型会失败，因为根据标准 [basic.types] 10.3:

A type is a literal type if it is: […] a reference type

但以下静态断言无法编译（在 MSVC2015RC 中）：

    static_assert( ::std::is_literal_type< ::std::wstring & >::value, "Nope" );

引用类型的定义是什么？

Answer 1

在两个 GCC and Clang 中都编译得很好，正如它应该的那样。您的编译器可能有错误的实现。

Answer 2

C++11 标准在 §8.3.2 中定义引用 [dcl.ref]:

1 In a declaration T D where D has either of the forms

& attribute-specifier-seqopt D1
&& attribute-specifier-seqopt D1

and the type of the identifier in the declaration T D1 is “derived-declarator-type-list T,” then the type of the identifier of D is “derived-declarator-type-list reference to T.” The optional attribute-specifier-seq appertains to the reference type. Cv-qualified references are ill-formed except when the cv-qualifiers are introduced through the use of a typedef (7.1.3) or of a template type argument (14.3), in which case the cv-qualifiers are ignored. [...]

2 A reference type that is declared using & is called an lvalue reference, and a reference type that is declared using && is called an rvalue reference. Lvalue references and rvalue references are distinct types. Except where explicitly noted, they are semantically equivalent and commonly referred to as references.

简单来说，引用类型就是声明为对其他类型的引用的类型。不过，关于他们的行为还有很多话要说。

引用类型和文字类型

reference types and literal types

c++

language-lawyer

c++11