Extra Parentheses in C Beyond Operator Precedence
While extra parentheses generally do not affect program behavior in C , there are specific contexts where they can alter the meaning of the code.
Preventing Argument-Dependent Name Lookup (ADNL)
Using parentheses around a function call, (fun)(arg), prevents argument-dependent name lookup. This means that namespace-scope friend functions or function template declarations that would otherwise be considered based on the argument types will not be included in the lookup.
Enabling Comma Operator in List Contexts
In list-like contexts such as function arguments and initializer lists, parentheses can enable the use of the comma operator where it would not apply in the regular form. For example, a, (b, c), d will have the comma operator applied to b and c, whereas a, b, c, d would not.
Ambiguity Resolution of Vexing Parses
Extra parentheses can resolve parsing ambiguities in certain declarations. The "Most Vexing Parse" is a famous example where a declaration can be误interpreted as a function if extra parentheses are not present.
Deduction of Reference in decltype Expressions
In decltype expressions, the presence or absence of parentheses affects the deduced referenceness. For example, decltype(e) deduces the type of e, while decltype((e)) deduces the type of the expression (e).
Preventing Preprocessor Macro Related Errors
Extra parentheses can prevent preprocessor macro related errors. For example, enclosing macro parameters in parentheses #define TIMES(A, B) (A) * (B); ensures that the operator precedence is correct.
The above is the detailed content of Do Extra Parentheses in C Affect Program Behavior?. For more information, please follow other related articles on the PHP Chinese website!

Gulc is a high-performance C library prioritizing minimal overhead, aggressive inlining, and compiler optimization. Ideal for performance-critical applications like high-frequency trading and embedded systems, its design emphasizes simplicity, modul

This article details C function return types, encompassing basic (int, float, char, etc.), derived (arrays, pointers, structs), and void types. The compiler determines the return type via the function declaration and the return statement, enforcing

This article explains C function declaration vs. definition, argument passing (by value and by pointer), return values, and common pitfalls like memory leaks and type mismatches. It emphasizes the importance of declarations for modularity and provi

This article details C functions for string case conversion. It explains using toupper() and tolower() from ctype.h, iterating through strings, and handling null terminators. Common pitfalls like forgetting ctype.h and modifying string literals are

This article examines C function return value storage. Small return values are typically stored in registers for speed; larger values may use pointers to memory (stack or heap), impacting lifetime and requiring manual memory management. Directly acc

This article analyzes the multifaceted uses of the adjective "distinct," exploring its grammatical functions, common phrases (e.g., "distinct from," "distinctly different"), and nuanced application in formal vs. informal

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

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


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool

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 English version
Recommended: Win version, supports code prompts!

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)
