[Issue 19637] New: Add a pre-condition to "in" and contains()

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=19637

          Issue ID: 19637
           Summary: Add a pre-condition to "in" and contains()
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: phobos
          Assignee: nobody at puremagic.com
          Reporter: porton at narod.ru

Accordingly https://dlang.org/phobos/std_range.html "in" and contains() require
sorted range.

Please add pre-condition to check if it is really sorted.

This will help to locate subtle errors.

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