C#

ROSLYN.RELIABILITY.CA2021 : Do not call Enumerable.Cast<T> or Enumerable.OfType<T> with incompatible types (C#)

See Roslyn-Detected C# Warning Classes for more information.

Summary

Enumerable.Cast and Enumerable.OfType require compatible types to function expectedly. The generic cast (IL 'unbox.any') used by the sequence returned by Enumerable.Cast will throw InvalidCastException at runtime on elements of the types specified. The generic type check (C# 'is' operator/IL 'isinst') used by Enumerable.OfType will never succeed with elements of types specified, resulting in an empty sequence. Widening and user defined conversions are not supported with generic types.

This check corresponds to Roslyn rule CA2021. For full rule details, see the Microsoft website: CA2021.

Properties

Class Name Do not call Enumerable.Cast<T> or Enumerable.OfType<T> with incompatible types (C#)
Significance reliability
Mnemonic ROSLYN.RELIABILITY.CA2021
Categories None
Availability Available for C# only.
Enabling Checks for this warning class are enabled by default. To disable them, add the following WARNING_FILTER rule to the project configuration file. 
WARNING_FILTER += discard class="Do not call Enumerable.Cast<T> or Enumerable.OfType<T> with incompatible types (C#)"

Relevant Configuration File Parameters

The following configuration file parameters affect checks for this warning class.