Why can't I throw exceptions from an expression-bodied member?

Question

Using expression-bodied members allows you to define the body of a method or property as a single expression without a return keyword (should it return something).

F

Answer 1

This feature is coming in C#7. From https://blogs.msdn.microsoft.com/dotnet/2016/08/24/whats-new-in-csharp-7-0/

It is easy to throw an exception in the middle of an expression: just call a method that does it for you! But in C# 7.0 we are directly allowing throw as an expression in certain places:

class Person
{
    public string Name { get; }
    public Person(string name) => Name = name ?? throw new ArgumentNullException(name);
    public string GetFirstName()
    {
        var parts = Name.Split(" ");
        return (parts.Length > 0) ? parts[0] : throw new InvalidOperationException("No name!");
    }
    public string GetLastName() => throw new NotImplementedException();
}

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Edit:

Updating this question to add links to newer info around how throw can now be used as an expression in expression-bodied members, ternary expressions and null-coalescing expressions, now that C# 7 is released:

What's new in C# 7 - Throw expressions.

New Features in C# 7.0.