MISRA C++:2008 Rule 2-5-1

Digraphs should not be used

Description

Rule Definition

Digraphs should not be used.1

Rationale

Digraphs are a sequence of two characters that are supposed to be treated as a single character. The checker flags use of these digraphs:

  • <%, indicating {

  • %>, indicating }

  • <:, indicating [

  • :>, indicating ]

  • %:, indicating #

  • %:%:, indicating ##

When developing or reviewing code with digraphs, the developer or reviewer can incorrectly consider the digraph as a sequence of separate characters.

Troubleshooting

If you expect a rule violation but Polyspace® does not report it, see Diagnose Why Coding Standard Violations Do Not Appear as Expected.

Check Information

Group: Lexical Conventions
Category: Advisory

Version History

Introduced in R2013b

See Also

Topics

1 All MISRA coding rules and directives are © Copyright The MISRA Consortium Limited 2021.

The MISRA coding standards referenced in the Polyspace Bug Finder™ documentation are from the following MISRA standards:

  • MISRA C:2004

  • MISRA C:2012

  • MISRA C:2023

  • MISRA C++:2008

  • MISRA C++:2023

MISRA and MISRA C are registered trademarks of The MISRA Consortium Limited 2021.