use MSBuild version-comparison functions

Author: smdn

src/NETSdkPreview.props

@@ -3,16 +3,14 @@ SPDX-FileCopyrightText: 2021 smdn <smdn@smdn.jp>
 SPDX-License-Identifier: MIT
 -->
 <Project Sdk="Microsoft.NET.Sdk">
-  <Import Project="$(MSBuildThisFileDirectory)..\NETSdkPreview.props" />
-
   <PropertyGroup>
     <TargetFrameworks>net6.0;netcoreapp3.1;net45;netstandard2.1;netstandard1.6</TargetFrameworks>
     <VersionPrefix>3.0.3</VersionPrefix>
     <VersionSuffix></VersionSuffix>
     <PackageValidationBaselineVersion>3.0.0</PackageValidationBaselineVersion>
   </PropertyGroup>
 
-  <PropertyGroup Condition=" '$(_NET7SdkAvailable)' == 'true' ">
+  <PropertyGroup Condition="$([MSBuild]::VersionGreaterThanOrEquals('$(NETCoreSdkVersion)', '7.0.0'))">
     <TargetFrameworks>net7.0;$(TargetFrameworks)</TargetFrameworks>
     <DefineConstants Condition="$(TargetFramework.StartsWith('net7'))">FEATURE_GENERIC_MATH;$(DefineConstants)</DefineConstants>
     <EnablePreviewFeatures Condition="$(TargetFramework.StartsWith('net7'))">true</EnablePreviewFeatures>
@@ -33,7 +31,7 @@ SPDX-License-Identifier: MIT
     <PackageReference Include="System.ValueTuple" Version="4.5.0" Condition="$(TargetFramework.StartsWith('net45')) or $(TargetFramework.StartsWith('net46')) or $(TargetFramework.StartsWith('netstandard1'))" />
   </ItemGroup>
 
-  <ItemGroup Condition=" '$(_NET7SdkAvailable)' == 'true' ">
+  <ItemGroup Condition="$([MSBuild]::VersionGreaterThanOrEquals('$(NETCoreSdkVersion)', '7.0.0'))">
     <PackageReference Include="System.Runtime.Experimental" Version="7.0.0-preview.2.22152.2" Condition="$(TargetFramework.StartsWith('net7'))" />
   </ItemGroup>
 

src/Smdn.Fundamental.UInt24n/Smdn.Fundamental.UInt24n.csproj

@@ -3,20 +3,18 @@ SPDX-FileCopyrightText: 2022 smdn <smdn@smdn.jp>
 SPDX-License-Identifier: MIT
 -->
 <Project Sdk="Microsoft.NET.Sdk">
-  <Import Project="$(MSBuildThisFileDirectory)..\..\src\NETSdkPreview.props" />
-
   <PropertyGroup>
     <TargetFrameworks>net6.0;net5.0;net48;net45;netcoreapp3.1</TargetFrameworks>
     <RootNamespace>Smdn</RootNamespace>
   </PropertyGroup>
 
-  <PropertyGroup Condition=" '$(_NET7SdkAvailable)' == 'true' ">
+  <PropertyGroup Condition="$([MSBuild]::VersionGreaterThanOrEquals('$(NETCoreSdkVersion)', '7.0.0'))">
     <TargetFrameworks>net7.0;$(TargetFrameworks)</TargetFrameworks>
     <DefineConstants Condition="$(TargetFramework.StartsWith('net7'))">FEATURE_GENERIC_MATH;$(DefineConstants)</DefineConstants>
     <EnablePreviewFeatures Condition="$(TargetFramework.StartsWith('net7'))">true</EnablePreviewFeatures>
   </PropertyGroup>
 
-  <ItemGroup Condition=" '$(_NET7SdkAvailable)' == 'true' ">
+  <ItemGroup Condition="$([MSBuild]::VersionGreaterThanOrEquals('$(NETCoreSdkVersion)', '7.0.0'))">
     <PackageReference Include="System.Runtime.Experimental" Version="7.0.0-preview.2.22152.2" Condition="$(TargetFramework.StartsWith('net7'))" />
   </ItemGroup>
 </Project>