Type inference at call site

Context: The C# compiler can automatically infer type parameters of a generic method based on the arguments passed. This avoids explicitly specifying types between angle brackets, making code cleaner and more readable.

Usage Example

using System;

public class Utils
{
    public static T Max<T>(T a, T b) where T : IComparable<T>
    {
        return a.CompareTo(b) > 0 ? a : b;
    }
}

class Program
{
    static void Main()
    {
        // Type inference: compiler deduces T = int
        int maxInt = Utils.Max(5, 10);
        Console.WriteLine(maxInt);

        // Inference: T = string
        string maxString = Utils.Max("abc", "def");
        Console.WriteLine(maxString);

        // Explicit (rarely needed):
        double maxDouble = Utils.Max<double>(1.5, 2.5);
        Console.WriteLine(maxDouble);
    }
}

Output console

dotnet run
10
def
2.5

Important notes

• Inference works based on arguments, not return values.
• If inference fails, you must specify the type explicitly.
• Methods with multiple type parameters may not infer all types.

Real-world usage example

LINQ – var result = list.Select(x => x.ToString()); infers T and TResult automatically.
See .NET docs on type inference.

Related sections

• 11.2.1 T MyMethod(T param)
• 11.4 Constraints