const Fred& or Fred const&: Which Placement Is Preferred in C ?

const Reference: Placement Before vs. After Type-specifier in C

In C , there's a choice between placing the const reference specifier (const Fred&) before or after the type-specifier (Fred const&). Though they appear identical semantically, the placement can have stylistic implications.

Semantic Equivalence

Syntactically, const Fred& and Fred const& represent the same type: a constant reference to a Fred object. The compiler interprets them interchangeably, thus eliminating any semantic differences.

Stylistic Preference

However, while semantically indifferent, there's a preference split when it comes to style. Some programmers favor placing the const before the type-specifier (const Fred&), citing its alignment with the C Programming Language book and the C standard. Others advocate for the post type-specifier placement (Fred const&), drawing inspiration from the style used in The C Programming Language by K&R and the C standard.

Advantages of const Fred&

• Follows the style employed by Stroustrup in his C book.
• Adheres to the style used in the C standard.

Advantages of Fred const&

• Aligns with the syntax used in K&R's seminal C book.
• Mirrors the style adopted in the C standard.
• May reduce the risk of misplaced characters, such as T const instead of const* T.

Parsing Considerations

The right-to-left parsing rule often influences style choices. However, it's worth noting that const Fred& can also be parsed meaningfully from right to left: a reference to a constant Fred object. Moreover, Fred const* can introduce ambiguity if interpreted as "pointer constant to T" instead of "pointer to constant T."

Conclusion

Ultimately, the choice between const Fred& and Fred const& boils down to personal preference. However, considering the established conventions in the C and C communities, const Fred& seems to have a slight edge in popularity.

The above is the detailed content of const Fred& or Fred const&: Which Placement Is Preferred in C ?. For more information, please follow other related articles on the PHP Chinese website!