search
HomeBackend DevelopmentC++How Can Inherited Classes Access Protected Variables in Templated Parent Classes in C ?

How Can Inherited Classes Access Protected Variables in Templated Parent Classes in C  ?

Accessing Inherited Variables from Templated Parent Class

The code snippet provided illustrates a scenario where the inherited class Bar attempts to access protected variables of its parent class Foo, which is a templated class. However, the compiler generates errors, leading to confusion regarding whether the compiler adheres to the standard.

According to the C standard, unqualified names within a template are considered non-dependent and must be resolved when the template is defined. Since the specialized base class templates may not be available during the template definition, unresolved unqualified names result in errors.

This applies to both variables and functions declared in the base class, as seen in the example where Bar can access a using qualified names or using declarations. The latter allows unqualified access within the derived class, resolving the initial error.

For instance, the following code modifications resolve the issue:

template<class t>
int Bar<t>::Perna(int u) {
  int c = Foo<t>::a * 4;  // Qualified name
  c = this->a * 4;        // Pointer to own instance
  using Foo<t>::a;
  c = a * 4;               // Using declaration
}</t></t></t></class>

By clarifying the lookup rules and providing alternative solutions, this explanation underscores the nuances of template resolution and helps developers understand the rationale behind the compiler's behavior.

The above is the detailed content of How Can Inherited Classes Access Protected Variables in Templated Parent Classes in C ?. For more information, please follow other related articles on the PHP Chinese website!

Statement
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
How does the C   Standard Template Library (STL) work?How does the C Standard Template Library (STL) work?Mar 12, 2025 pm 04:50 PM

This article explains the C Standard Template Library (STL), focusing on its core components: containers, iterators, algorithms, and functors. It details how these interact to enable generic programming, improving code efficiency and readability t

How do I use algorithms from the STL (sort, find, transform, etc.) efficiently?How do I use algorithms from the STL (sort, find, transform, etc.) efficiently?Mar 12, 2025 pm 04:52 PM

This article details efficient STL algorithm usage in C . It emphasizes data structure choice (vectors vs. lists), algorithm complexity analysis (e.g., std::sort vs. std::partial_sort), iterator usage, and parallel execution. Common pitfalls like

How do I handle exceptions effectively in C  ?How do I handle exceptions effectively in C ?Mar 12, 2025 pm 04:56 PM

This article details effective exception handling in C , covering try, catch, and throw mechanics. It emphasizes best practices like RAII, avoiding unnecessary catch blocks, and logging exceptions for robust code. The article also addresses perf

How do I use rvalue references effectively in C  ?How do I use rvalue references effectively in C ?Mar 18, 2025 pm 03:29 PM

Article discusses effective use of rvalue references in C for move semantics, perfect forwarding, and resource management, highlighting best practices and performance improvements.(159 characters)

How do I use ranges in C  20 for more expressive data manipulation?How do I use ranges in C 20 for more expressive data manipulation?Mar 17, 2025 pm 12:58 PM

C 20 ranges enhance data manipulation with expressiveness, composability, and efficiency. They simplify complex transformations and integrate into existing codebases for better performance and maintainability.

How do I use move semantics in C   to improve performance?How do I use move semantics in C to improve performance?Mar 18, 2025 pm 03:27 PM

The article discusses using move semantics in C to enhance performance by avoiding unnecessary copying. It covers implementing move constructors and assignment operators, using std::move, and identifies key scenarios and pitfalls for effective appl

How does dynamic dispatch work in C   and how does it affect performance?How does dynamic dispatch work in C and how does it affect performance?Mar 17, 2025 pm 01:08 PM

The article discusses dynamic dispatch in C , its performance costs, and optimization strategies. It highlights scenarios where dynamic dispatch impacts performance and compares it with static dispatch, emphasizing trade-offs between performance and

C language data structure: data representation and operation of trees and graphsC language data structure: data representation and operation of trees and graphsApr 04, 2025 am 11:18 AM

C language data structure: The data representation of the tree and graph is a hierarchical data structure consisting of nodes. Each node contains a data element and a pointer to its child nodes. The binary tree is a special type of tree. Each node has at most two child nodes. The data represents structTreeNode{intdata;structTreeNode*left;structTreeNode*right;}; Operation creates a tree traversal tree (predecision, in-order, and later order) search tree insertion node deletes node graph is a collection of data structures, where elements are vertices, and they can be connected together through edges with right or unrighted data representing neighbors.

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
3 weeks agoBy尊渡假赌尊渡假赌尊渡假赌
R.E.P.O. Best Graphic Settings
3 weeks agoBy尊渡假赌尊渡假赌尊渡假赌
R.E.P.O. How to Fix Audio if You Can't Hear Anyone
3 weeks agoBy尊渡假赌尊渡假赌尊渡假赌

Hot Tools

MinGW - Minimalist GNU for Windows

MinGW - Minimalist GNU for Windows

This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.

Dreamweaver Mac version

Dreamweaver Mac version

Visual web development tools

Safe Exam Browser

Safe Exam Browser

Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor