Useless upcast¶
ID: cs/useless-upcast
Kind: problem
Security severity:
Severity: warning
Precision: medium
Tags:
- maintainability
- language-features
- external/cwe/cwe-561
Query suites:
- csharp-security-and-quality.qls
Click to see the query in the CodeQL repository
In most situations, casting an expression where there exists a corresponding implicit conversion serves no purpose.
Recommendation¶
Remove the redundant cast.
Example¶
In this example, casting explicitly from Sub to Super is redundant.
class Bad
{
class Super {}
class Sub : Super {}
void M()
{
var sub = new Sub();
Super super = (Super)sub;
}
}
The code above can be fixed, either by removing the explicit cast, or by making super an implicitly typed (var) variable.
References¶
Microsoft: Casting and Type Conversions.
Common Weakness Enumeration: CWE-561.