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Re: map[string_view] not compiling

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Bo Persson <bo@bo-persson.se> writes:
>Not an expert, but operator[] takes a Key parameter, which is 
>std::string here. And string_view is not implicitly convertible to 
>std::string.

  Even more not an expert, but I take it from the Web that
  even convertibililty alone would not suffice. The Web says:

|Three things are required for something like this to happen:
|
|1. The map's comparator must be a transparent comparator
|
|2. The at() method must have an overload that participates in
|   overload resolution when the container has a transparent
|   comparator.
|
|3. the parameter must be convertible to the map's key_type.
|
|Neither of these are true in your example. The default
|std::less comparator is not a transparent comparator, there
|is no such overload for at(), and std::string does not have
|an implicit conversion from std::string_view.
|
The World-Wide Web (2021).

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