Avoid unintentionally converting between float and double multiple times
by just using double everywhere. Also, remove the unused `int` versions
of their constructors.
This is to make it easier to bounds-check their values during parsing.
Length is left out because many length units are relative to the
context in which they are used, and so we cannot easily compare `10px`
and `1em`, for example.
This makes it possible to do arithmetic on them without having to
resolve to their canonical unit, which often requires context
information that is not available until the last minute. For example, a
Length cannot be resolved to px without knowing the font size, parent
element's size, etc.
Only Length currently requires such context, but treating all these
types the same means that code that manipulates them does not need to
know or care if a new unit gets added that does require contextual
information.
This will make it easier to support both string types at the same time
while we convert code, and tracking down remaining uses.
One big exception is Value::to_string() in LibJS, where the name is
dictated by the ToString AO.
We have a new, improved string type coming up in AK (OOM aware, no null
state), and while it's going to use UTF-8, the name UTF8String is a
mouthful - so let's free up the String name by renaming the existing
class.
Making the old one have an annoying name will hopefully also help with
quick adoption :^)
C++20 can automatically synthesize `operator!=` from `operator==`, so
there is no point in writing such functions by hand if all they do is
call through to `operator==`.
This fixes a compile error with compilers that implement P2468 (Clang
16 currently). This paper restores the C++17 behavior that if both
`T::operator==(U)` and `T::operator!=(U)` exist, `U == T` won't be
rewritten in reverse to call `T::operator==(U)`. Removing `!=` operators
makes the rewriting possible again.
See https://reviews.llvm.org/D134529#3853062
Which is to say, a T where `is_calculated()` is false.
As is becoming a repeating theme with CSS types, we have two states for
a FooPercentage that is a `calc()` expression: Either the FooPercentage
holds the CalculatedStyleValue directly, or it holds a Foo which itself
holds the CalculatedStyleValue. The first case was already handled to
return Foo, and with this patch, the second is too. :^)
