* Allow one to get a `Popularity` where `.rating` is always between 1 and 5
via `TagValue::toScaledPopularity()` (or a "raw" scale by specifying the
corresponding tag format)
* Allow one to assign a `Popularity` with `.scale = TagType::Unspecified`
and `.rating` between 1 and 5 (or a "raw" scale by specifying the
corresponding tag format). It will then be converted internally to
the required scale (whatever the tag format internally uses)
* Ensure all tag formats with popularity/rating field use
`TagValue::toScaledPopularity()` internally when a `Popularity`
object is assigned
* Ensure all tag formats with popularity/rating field store the rating as
popularity object to preserve the scaling information
* Keep passing raw strings around working
* `TagValue::toString()` still does *no* scaling
* `TagValue::toScaledPopularity()` does *no* scaling for text values
and instead just assigns the specified scale
* See https://github.com/Martchus/tagparser/issues/23
This would allow implementing a way to convert between different scales and
which in turn would allow the UI to provide an editor with a generic scale
(e.g. stars) instead of only allowing to edit raw values as string.
This also make it assume that a single number is meant to be the rating
(instead of the user). That should make editing the rating a bit more
straight forward (if one doesn't care about the user and play counter).
This should fix all non-erros, leaving only warnings which
are indeed potential problems.
The following warnings should be safe to ignore:
* Conversions of various offsets from uint64 to
std::streamoff/int64 are safe because such offsets have
been obtained via tellg() and other functions
returning std::streamoff in the first place.
* It also works vice-versa since tellg() should not
return negative offsets with exceptions enabled.
* Conversions from char to unsigned char are also ok.
* Unused diag arguments can be ignored (those might be
useful later).
* Annotate all intended fallthoughs.
Martchus