A few minutes ago I needed to "fold" an array into a hash representing a bag/set. That is, from [a, b, c] I wanted to create {a => 1, b => 1, c => 1}. Without thinking much, I slapped:

my %bag = map {($_, 1)} @arr;
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And now I wonder on the merits of this technique. I recall seeing it discussed in the monastery before, I can't don't know what to look for in the Supersearch. Any fellow monks with memory better than mine ?

What I want to know, basically, is whether it's a Good Way (TM), what are the alternatives, etc.