CA1005: Avoid excessive parameters on generic types
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Item | Value |
---|---|
TypeName | AvoidExcessiveParametersOnGenericTypes |
CheckId | CA1005 |
Category | Microsoft.Design |
Breaking Change | Breaking |
Cause
An externally visible generic type has more than two type parameters.
Rule Description
The more type parameters a generic type contains, the more difficult it is to know and remember what each type parameter represents. It is usually obvious with one type parameter, as in List<T>
, and in certain cases with two type parameters, as in Dictionary<TKey, TValue>
. If more than two type parameters exist, the difficulty becomes too great for most users (for example, TooManyTypeParameters<T, K, V>
in C# or TooManyTypeParameters(Of T, K, V)
in Visual Basic).
How to Fix Violations
To fix a violation of this rule, change the design to use no more than two type parameters.
When to Suppress Warnings
Do not suppress a warning from this rule unless the design absolutely requires more than two type parameters. Providing generics in a syntax that is easy to understand and use reduces the time that is required to learn and increases the adoption rate of new libraries.
Related Rules
CA1010: Collections should implement generic interface
CA1000: Do not declare static members on generic types
CA1002: Do not expose generic lists
CA1006: Do not nest generic types in member signatures
CA1004: Generic methods should provide type parameter
CA1003: Use generic event handler instances
CA1007: Use generics where appropriate