Awesome
IndexRange
This repository provides implementations (copied from corefx)
of System.Index
and System.Range
for netstandard2.0
and .NET Framework.
This lets you use the new C# 8.0 index and range features in projects that target
.NET Framework or netstandard2.0
.
Installing
The package is available on NuGet. To install, run:
dotnet add package IndexRange
Build Status
Using Range with Arrays
The C# compiler needs the RuntimeHelpers.GetSubArray<T>
method to be available to create subranges from arrays. This method is only available in netstandard2.1
and .NET Core 3.0, so creating subranges from arrays will fail to compile in .NET Framework.
Use Span<T>
A workaround is to add a reference to System.Memory and use Span<T>
. Not only does this compile, it's much more
efficient as it doesn't create a new array and copy the sliced data to it:
int[] array = new[] { 1, 2, 3, 4, 5, 6 };
// don't do this:
// var slice = array[1..^1];
// do this:
var slice = array.AsSpan()[1..^1];
Define GetSubArray<T>
The other fix is to define the necessary method in your source code. Copy the following code into your project:
https://gist.github.com/bgrainger/fb2c18659c2cdfce494c82a8c4803360
That type is not in this NuGet package so that the C# compiler doesn't warn that The predefined type 'RuntimeHelpers' is defined in multiple assemblies
.