c++ - 在 C++11 中，如何指定隐式 "this"参数 "[[carries_dependency]]"？

Question

在 [dcl.attr.depend]/1 中，我读到:

The attribute[...] carries_dependency [...] may be applied to the declarator-id of a parameter-declaration in a function declaration or lambda, in which case it specifies that the initialization of the parameter carries a dependency to (1.10) each lvalue-to-rvalue conversion (4.1) of that object. The attribute may also be applied to the declarator-id of a function declaration, in which case it specifies that the return value, if any, carries a dependency to the evaluation of the function call expression.

我缺少的是一种将属性应用于隐式 this 参数的方法。

例如，考虑这个自由函数:

void fun(int i, Foo * [[carries_dependency]] f);

它是等效的(但对于属性)成员版本:

void Foo::fun(int i); // can't add [[carries_dependency]] here?

Answer 1

我不确定并且没有支持此测试的编译器，但这里有一个可能性:我认为语法 [gram.decl] 表明您应该能够把它(“属性-specifier_opt") 在您放置“const”以指示常量 this 指针(“cv-qualifier-seq_opt”)的同一位置，这是有道理的:

parameters-and-qualifiers:
    ( parameter-declaration-clause ) attribute-specifier_opt cv-qualifier-seq_opt
        ref-qualifier_opt exception-specification_opt

例如

struct X{
    void f(int i) [[carries_dependency]];
};