Use C# 8 nullable reference types

[Happypig375]

Reference https://github.com/manuelroemer/Nullable.

[WhiteBlackGoose]

What's the point of using it?

[Happypig375]

Making clear whether parameters are nullable lets downstream users avoid unintentionally passing nulls into methods.

[Happypig375]

This is not done. Request reopen.

[Happypig375]

𝖳𝗁𝗂𝗌 𝗂𝗌 𝗇𝗈𝗍 𝖽𝗈𝗇𝖾. 𝖱𝖾𝗊𝗎𝖾𝗌𝗍 𝗋𝖾𝗈𝗉𝖾𝗇.

[MomoDeve]

Could you at least put examples where this feature can be used in our library? From my experience, almost always methods parameters must not be null in AM

[Happypig375]

From my experience, almost always methods parameters must not be null in AM

Then that is great! After enabling nullable reference types, little code changes will be required.

[Happypig375]

Could you at least put examples where this feature can be used in our library?

Put

<LangVersion>8.0</LangVersion>
<Nullable>enable</Nullable>
<WarningsAsErrors>nullable</WarningsAsErrors>

in the csprojs.

[siriak]

@Happypig375 maybe you could do that and make a PR?

[Happypig375]

@siriak The green light is needed or LayoutFarm/Typography#192 will happen again.

[siriak]

@Happypig375 agree, good point.

[MomoDeve]

We will look at the changes. If all unit tests are passed, we will merge it.
You can split your pull request into multiple ones, to let us review changes in portions

[Happypig375]

I have started to implement this.