Implement Add on Option types #5328
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This will allow you to use the + operator to add together any two Options, assuming that the contents of each Option likewise implement +. So Some(4) + Some(1) == Some(5), and adding with None leaves the other value unchanged. This might be monoidic? I don't know what that word means!
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I don't think this should require |
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I think this should work with any binop-with-an-identity (which, wikipedia tells me, is almost a monoid! I don't know whether associativity is a relevant dimension of trying to generalize this. I would, for the sake of not scaring off readers, prefer we not wind up with something called "monoid" in the library) |
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@thestinger Yes, I initially tried without the Copy bound and it yelled at me. I'd be happy to forgo it if there's a better solution. |
This will allow you to use the `+` operator to add together any two Options, assuming that the contents of each Option likewise implement `+`. So Some(4) + Some(1) == Some(5), and adding with None leaves the other value unchanged. This might be monoidic? I don't know what that word means!
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Can we now go on and make |
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What about other operators? |
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@sanxiyn I'd need some guidance as to what that would mean. For example: let foo = None;
let bar = Some(4);
let baz = foo - bar; // what is baz?The semantics are easy for addition. Not sure about the rest. |
Also fixes the same for float_arithmetic. changelog: integer_arithmetic,float_arithmetic: fix false negatives with references on integers Fixes rust-lang#5328
…flip1995 integer_arithmetic: detect integer arithmetic on references. changelog: integer_arithmetic fix false negatives with references on integers Fixes rust-lang#5328
This will allow you to use the
+operator to add together any twoOptions, assuming that the contents of each Option likewise implement
+. So Some(4) + Some(1) == Some(5), and adding with None leaves theother value unchanged.
This might be monoidic? I don't know what that word means!