https://issues.dlang.org/show_bug.cgi?id=23457

          Issue ID: 23457
           Summary: std.string.wrap has no policy on how it counts columns
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: normal
          Priority: P1
         Component: phobos
          Assignee: nobody@puremagic.com
          Reporter: Ajieskola@gmail.com

There's no hint in documentation of `std.string.wrap` whether it counts the columns by code unit or by code point. Moreover, the function does not even settle on one or the other. Example:

```D
// €€ €€
// €€
//
wrap("€€ €€ €€", 18).writeln;
// €€ €€ €€
//
wrap("€€ €€", 18, "€€ ").writeln;
```

These both should print the same result. While either result will do, I'm inclined to think the result should be the one with all '€':s in the same line. The purpose of the function is to fit characters in a certain space, and characters take the same amount of space regardless of encoding.

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