在非循环对象上,为什么不用C ++调用带有public-const和private-nonconst重载的方法的const版本? [英] On a nonconst object, why won't C++ call the const version of a method with public-const and private-nonconst overloads?
问题描述
class C
{
public:
void foo() const {}
private:
void foo() {}
};
int main()
{
C c;
c.foo();
}
MSVC 2013不喜欢这样:
MSVC 2013 doesn't like this:
> error C2248: 'C::foo' : cannot access private member declared in class 'C'
我投射到 const
引用,它的工作原理:
If I cast to a const
reference, it works:
const_cast<C const &>(c).foo();
为什么我不能调用 const
方法对非 const
对象?
Why can't I call the const
method on the nonconst
object?
推荐答案
/ p>
From the standard:
13.3.3如果一个最好的可行函数存在并且是唯一的,重载解析成功并产生结果。
否则重载解析失败,调用失败。 当重载解析成功时,
在使用它的上下文中无法访问最佳可行函数(第11条),程序是
格式不正确。 p>
13.3.3 If a best viable function exists and is unique, overload resolution succeeds and produces it as the result. Otherwise overload resolution fails and the invocation is ill-formed. When overload resolution succeeds, and the best viable function is not accessible (Clause 11) in the context in which it is used, the program is ill-formed.
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