Using the New Static Feature in C# 6.0

MSCORELIB Classes that Work With Using Static in C# 6.0

While writing another MSDN magazine article on C# 6.0 (the third because the language continues to improve) I was looking for a good example of when to use the new “using static” feature.  Towards this effort, I used PowerShell to crawl through all the MSCORELIB types and output the ones meeting the following criteria:

• The type is public
• The type is static (at the CIL level this is represented by sealed and abstract)
• There exists members on the type that are not extension members

The resulting list of “common” types is relatively small (given the total number of types is over 3,000).

System.Tuple
System.BitConverter
System.Buffer
System.Console
System.Convert
System.Environment
System.GC
System.GC
System.Math
System.Threading.Interlocked
System.Threading.Tasks.Parallel
System.Nullable
System.Diagnostics.Contracts.Contract
Microsoft.Win32.Registry
System.Runtime.InteropServices.Marshal
System.IO.Directory
System.IO.File
System.IO.Path
System.Runtime.CompilerServices.RuntimeHelpers
System.Security.SecurityManager

That’s 20 types out of 3,000 and some might argue that many of these are not so common or wouldn’t be used with the feature any way.

In addition, there are some ancillary (what I consider rarely used) types:

System.Deployment.Internal.InternalApplicationIdentityHelper
 System.Deployment.Internal.InternalActivationContextHelper
 System.Threading.Monitor
 System.Threading.ThreadPool
 System.Threading.Volatile
 System.Threading.LazyInitializer
 System.Collections.StructuralComparisons
 System.Collections.Concurrent.Partitioner
 System.Diagnostics.Contracts.Internal.ContractHelper
 System.Runtime.CompilerServices.ContractHelper
 System.Runtime.Serialization.FormatterServices
 System.Globalization.CharUnicodeInfo
 System.Security.Policy.ApplicationSecurityManager
 System.Runtime.InteropServices.ComEventsHelper
 System.Runtime.InteropServices.WindowsRuntime.WindowsRuntimeMarshal
 System.Runtime.InteropServices.WindowsRuntime.WindowsRuntimeMetadata
 System.Runtime.GCSettings
 System.Runtime.ProfileOptimization
 System.Runtime.Remoting.RemotingConfiguration
 System.Runtime.Remoting.RemotingServices
 System.Runtime.Versioning.VersioningHelper
 System.Runtime.Versioning.CompatibilitySwitch

Overall, this seems like a relatively small number rendering the new language feature (at least for MSCORELIB base classes), less useful that I originally expected.

Parenthetically, for those curious about the PowerShell script, the listing below shows what I used:

Function Test-IsStaticType {
    [CmdletBinding()]param(
        [Parameter(Mandatory, ValueFromPipeline)][Type]$Type,
        [bool]$IsPublic = $true  #ToDo: Add pipe and mandetory
    )
    return ($Type.IsSealed -and $Type.IsAbstract) -and ($IsPublic -and $Type.IsPublic) # -and (!$Type.IsValueType) -and $Type.IsPublic 
}

 #ToDo: Convert to support Get-Member output of type Microsoft.PowerShell.Commands.MemberDefinition (possibly in addition to MethodInfo support)
Function Test-IsExtensionMethod {
   [CmdletBinding()]param(
        [Parameter(Mandatory, ValueFromPipeline)][System.Reflection.MethodInfo]$Method
    )
    return $Method.IsStatic -and ($Method.CustomAttributes.Count -gt 0) -and
        ($Method.CustomAttributes.AttributeType -contains [System.Runtime.CompilerServices.ExtensionAttribute] )
}

Function Get-ReflectionExtensionMemebers {
   [CmdletBinding()]param(
        [Parameter(Mandatory, ValueFromPipeline)][Type]$Type
    )

    $Type.GetMethods() | ?{ Test-IsExtensionMethod $_  }
}

[reflection.assembly]::GetAssembly([system.console]).GetTypes() | ?{ Test-IsStaticType $_ } |  %{ 
    $methods = $_.GetMethods() | ?{ -not (Test-IsExtensionMethod $_) } | ?{ $_.IsStatic }
    if($_.GetProperties().Length -gt 0) {
        $properties = $_ | Get-Member -Static -MemberType Property
    }
    if( ($methods -ne $null) -and ($properties -ne $null) ) {
        Write-OUtput $_.FullName # -ForegroundColor Green
        $methods | select -ExpandProperty name | select -unique | ?{
            ($_ -notlike "get_*") } | ?{ ($_ -notlike "set_*") 
        } | %{
            #Write-Host "`t$($_)" -ForegroundColor White
        }
    }
}