This is a deliberate design choice. As written in The Swift Programming Language:<br><br>"Use UInt only when you specifically need an unsigned integer type with the same size as the platform’s native word size. If this is not the case, Int is preferred, even when the values to be stored are known to be non-negative. A consistent use of Int for integer values aids code interoperability, avoids the need to convert between different number types, and matches integer type inference, as described in Type Safety and Type Inference."<br><br>You are correct that arrays with count greater than Int.max are unsupported.<br><div class="gmail_quote"><div dir="ltr">On Thu, Mar 16, 2017 at 11:13 G Alexander via swift-evolution <<a href="mailto:swift-evolution@swift.org">swift-evolution@swift.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<div class="gmail_msg">All,<br class="gmail_msg">
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<div class="gmail_msg">Why does swift fails to fully implement UInt in any object, arrays, sequence, range, etc<br class="gmail_msg">
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Initializer for Range, from "<a href="http://swiftdoc.org/v3.1/type/Range/" class="gmail_msg" target="_blank">http://swiftdoc.org/v3.1/type/Range/</a>"<br class="gmail_msg">
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For example, passing a closed range with an upper bound of Int.max triggers a runtime error, because the resulting half-open range would require an upper bound of Int.max + 1, which is not representable as an Int.<br class="gmail_msg">
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So any algorithm that needs large arrays such that, UInt64.max > index > Int64 too bad?</div>
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