VinlandSolutions.CommonCore.Shims 1.0.0-pre.1

Vinland Solutions CommonCore.Exceptions Library

NOTE: This project should only be used by legacy pre-dotnet core projects and libraries that multi-target net standard 2.0 to reach such projects.

CommonCore.Shims is a .Net Standard 2.0 library that provides shims for C# 9 features like collection slicing and initializable properties.

Installation

The official release versions of the CommonCore.Shims library are hosted on NuGet and can be installed using the standard console means, or found through the Visual Studio NuGet Package Managers.

This library is compatible with projects targeting at least .Net Framework 4.6.1, .Net Core 2.0, or .Net 5.

Usage

This library does not have special usage of it's own. It simply enables C# language features that are usually present but unusable in projects targeting lower than net standard 2.1. When included in multitargeting projects, the library should be conditionally referenced so it is only included for the net standard 2.0 target.

    <ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">
        <PackageReference Include="VinlandSolutions.CommonCore.Shims" Version="X.Y.Z" />
    </ItemGroup>

It may also be necessary to explicitly enable C# 9 language features, in which case a LangVersion element must be added to the project file.

    <PropertyGroup>
        <TargetFrameworks>netstandard2.1;netstandard2.0</TargetFrameworks>
        <LangVersion>9.0</LangVersion>
    </PropertyGroup>

Otherwise, usage is normal as per the various shimmed features.

Slicing collections:

int[] array = new int[] { 9, 5, 1 };
int[] subarray;
subarray = array[1..];// { 5, 1 }
subarray = array[..^1];// { 9, 5 }
subarray = array[1..^1];// { 5 }

Externally initializable properties:

public class SomeClass
{
    public int InitProp { get; init; } = 10;
}

var sc = new SomeClass();
Console.WriteLine(sc.InitProp);// InitProp == 10
sc = new SomeClass() { InitProp = 5 };
Console.WriteLine(sc.InitProp);// InitProp == 5
sc.InitProp = 0;// Error

Some code analysis attributes:

public static bool TryParse(
    [NotNullWhen(true)] object? input,
    [NotNullWhen(true), MaybeNullWhen(false)] out SomeType? output)
{
    // if input is not null and can parse input,
    // then set output to result and return true,
    // else set output null and return false.
}

Projects

The CommonCore.Shims repository is composed of three projects with the listed dependencies:

• CommonCore.Shims: The dotnet standard 2.0 library project.
  • System.Memory
  • Microsoft.Bcl.HashCode
• CommonCore.Shims.Docs: The project for generating api documentation.
  • DocFX
• CommonCore.Shims.Tests: The project for running unit tests and generating coverage reports.
  • xUnit
  • FluentAssertions

Links

• Repository: https://gitlab.com/commoncorelibs/commoncore-shims
• Issues: https://gitlab.com/commoncorelibs/commoncore-shims/issues
• Docs: https://commoncorelibs.gitlab.io/commoncore-shims/index.html
• Nuget: https://www.nuget.org/packages/VinlandSolutions.CommonCore.Shims/

Credits

This library simply wraps some dotnet types that are built-in for net standard 2.1 and greater, so thanks goes to the dotnet team.

• DotNet