Home > Backend Development > C++ > body text

Why Does the Compiler Require `b->A::DoSomething()` Instead of `b->DoSomething()` in This C Code?

DDD
Release: 2024-11-05 12:37:02
Original
1046 people have browsed it

Why Does the Compiler Require `b->A::DoSomething()` Instead of `b->DoSomething()` in This C   Code? 
A::DoSomething()` Instead of `b->DoSomething()` in This C Code? " />

C Overload Resolution

In the given code example, the compiler requires the explicit use of b->A::DoSomething() instead of b->DoSomething() due to the concept of "overload resolution".

Overload resolution determines which function overload is called based on the type and number of arguments. In this case, the compiler considers the method DoSomething() within the scope of the class B first. Since there is a method with the same name and parameters within B, the compiler attempts to resolve the overload within B.

However, the method DoSomething() within A is also a valid overload. To explicitly access this overload, the scope operator :: is used to specify that the DoSomething() method belongs to the base class A.

One possible solution to avoid this issue would be to "pull down" the overload from A into the scope of B using the using keyword. This effectively allows access to A::DoSomething() directly within B. Here's an example:

<code class="cpp">class B : public A {
public:
    using A::DoSomething;
    // Additional methods or members
};</code>
Copy after login

Now, within the scope of B, the method DoSomething() can be called without the A:: prefix, as it is considered an overload within B due to the using directive.

The above is the detailed content of Why Does the Compiler Require `b->A::DoSomething()` Instead of `b->DoSomething()` in This C Code?. For more information, please follow other related articles on the PHP Chinese website!

source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template