Null Coalescence and Lambdas

Question

This answer to another question of mine did not compile, though on the surface it seems it should (this isn't the same question, I can rewrite the other answer to work for my other question).

Given

private Func<MyT, bool> SegmentFilter { get; set; }

public MyConstructor(Func<MyT, bool> segmentFilter = null)
{
    // This does not compile
    // Type or namespace mas could not be found
    SegmentFilter = segmentFilter ?? (mas) => { return true; };

    // This (equivalent?) form compiles just fine
    if (segmentFilter == null) 
    {
        SegmentFilter = (mas) => { return true; };
    }
    else
    {
        SegmentFilter = segmentFilter;
    }
}

Why is the compiler running into trouble with the null coalescent operator, but not with the syntax-sugar-free if/else version?

Answer 1

That's because ?? has higher precedence than =>. You can easily fix that by wrapping your lambda into ():

SegmentFilter = segmentFilter ?? ((mas) => { return true; });