You can use attributes in the JetBrains.Annotations namespace to annotate your own code to make ReSharper analyze it with greater accuracy and insight.
MrAdvice allows to weave aspects at build-time (just like PostSharp, but free as in free beer). Write your own aspects in the form of attributes and apply them to target methods or properties. This version does not require any dependency (on the opposite of MrAdvice.Fody which requires Fody).
A source code only package which allows you to use .NET's new nullable attributes in older target frameworks like .NET Standard 2.0 or the "old" .NET Framework.
This package does not contain any compiled binaries, but instead adds the attribute classes as C# source code to your project. Because...
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Obsolete! Use https://www.nuget.org/packages/MrAdvice/ instead! MrAdvice allows to weave aspects at build-time (just like PostSharp, but free as in free beer). Write your own aspects in the form of attributes and apply them to target methods or properties.