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I really enjoy some of the optimization details like when the memory overhead of Option<> can be elided completely. Other languages with Options will actually toss data up on the heap that doesn't need to be because it is in a Option and, or at the very least always take up a byte with the tag.

Details like this let you use the safer and more ergonomic solutions by default rather than having to worry if they are worth the overhead.

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Indeed. Also more broadly Rust's types do not exist at runtime, and so you get the New Type idiom. If we care about the difference between a Row and a Column in the program, we can create distinct Row and Column types, and Rust won't allow you to use a Row when you need a Column, even if they're both "just integers", yet at runtime there's no cost for this, if the obvious representation of Row and Column is a 32-bit integer that fits nicely in the general purpose registers and takes up 4 bytes of RAM, that's how they're both represented at runtime.

You can do a lot of this in languages like C++ but there are some pernicious limits that Rust didn't have e.g. C++ can't conceive of Zero Size Types.

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