MISRA C++:2023 Rule 5.0.1

Trigraph-like sequences should not be used

Since R2024b

Description

Rule Definition

Trigraph-like sequences should not be used.

Rationale

You denote trigraphs with two question marks followed by a specific third character (for instance,'??-' represents a '~' (tilde) character and '??)' represents a ']'). These trigraphs can cause accidental confusion with other uses of two question marks.

For instance, the string

"(Date should be in the form ??-??-??)"

is transformed to

"(Date should be in the form ~~]"

but this transformation might not be intended.

Polyspace Implementation

The rule checker reports violations on use of trigraphs, whether used in strings or otherwise.

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 R2024b