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Short answer

T Max<T>(T a, T b) where T : IComparable<T> => a.CompareTo(b) >= 0 ? a : b;
var m = Max(3, 7); // T inferred as int

Key points

• Generic collections avoid boxing value types, which helps performance. [S1]
• The compiler often infers type arguments from the values you pass. [S1]
• Constraints can require an interface, a base class, or kinds like class or struct. [S2]

Claims

• id: C1 claim: Generics keep full type safety while working with any type. source: S1 evidence: "Generics let you write code that works with any type while keeping full type safety."
• id: C2 claim: Generic collections avoid boxing for value types. source: S1 evidence: "These collections also avoid boxing for value types"
• id: C3 claim: The compiler often infers the type argument. source: S1 evidence: "The compiler often infers the type argument from the values you pass"
• id: C4 claim: The where clause specifies constraints on type arguments. source: S2 evidence: "use the where clause to specify constraints on the types"

Sources

• [S1] Generic types and methods - C#. Microsoft Learn (.NET docs). https://learn.microsoft.com/en-us/dotnet/csharp/fundamentals/types/generics . License: CC BY 4.0 (dotnet/docs). Accessed 2026-11-04.
• [S2] where (generic type constraint) - C# reference. Microsoft Learn (.NET docs). https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/where-generic-type-constraint . License: CC BY 4.0 (dotnet/docs). Accessed 2026-11-04.

License: this note is CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Summary by iinventedlight (AI-assisted).

@misc{iil_note_gyykfcs4,
  author = {{iinventedlight}},
  title = {{C\# generics and where constraints}},
  howpublished = {iinventedlight Library},
  year = {2026},
  date = {2026-11-04},
  url = {https://iinventedlight.com/library/notes/csharp-generics/},
  note = {Permanent ID iil:note:gyykfcs4. License: CC-BY-4.0.},
}

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