Merge pull request #8 from hikarin522/develop

v0.4.0

.config/dotnet-tools.json

@@ -3,7 +3,7 @@
   "isRoot": true,
   "tools": {
     "dotnet-t4": {
-      "version": "2.2.1",
+      "version": "2.3.1",
       "commands": [
         "t4"
       ]

Directory.Build.props

@@ -3,7 +3,7 @@
     <LangVersion>latest</LangVersion>
     <Nullable>enable</Nullable>
 
-    <Version>0.3.4</Version>
+    <Version>0.4.0</Version>
     <Authors>hikarin522</Authors>
     <Copyright>(c) 2022 hikarin522.</Copyright>
     <PackageLicenseExpression>MIT</PackageLicenseExpression>

README.md

@@ -8,7 +8,7 @@ C# source generator to generate efficient and type-safe variant types for unmana
 ## Usage
 
 ```cs
-using System.ValueVariant;
+using ValueVariant;
 
 [ValueVariant]
 public readonly partial struct SampleVariant: IValueVariant<SampleVariant, int, long, float> { }
@@ -60,3 +60,35 @@ readonly partial struct SampleVariant: IEquatable<SampleVariant>
     ...
 }
 ```
+
+## Type conversion between variant types
+
+```cs
+[ValueVariant]
+public readonly partial struct SampleVariant1 : IValueVariant<SampleVariant1, int, Guid, DateTime>
+{
+    public static explicit operator SampleVariant1(SampleVariant2 value)
+        => value.TryCast(out var result) ? result : throw new InvalidCastException();
+
+    public readonly bool TryCast(out SampleVariant2 result)
+    {
+        if (this == default) { result = default; return true; }
+        this.Accept(SampleVariant2.DefaultConverter.Instance, out result);
+        return result != default;
+    }
+}
+
+[ValueVariant]
+public readonly partial struct SampleVariant2 : IValueVariant<SampleVariant2, Guid, DateTime, int, long, bool>
+{
+    public static explicit operator SampleVariant2(SampleVariant1 value)
+        => value.TryCast(out var result) ? result : throw new InvalidCastException();
+
+    public readonly bool TryCast(out SampleVariant1 result)
+    {
+        if (this == default) { result = default; return true; }
+        this.Accept(SampleVariant1.DefaultConverter<long, bool>.Instance, out result);
+        return result != default;
+    }
+}
+```

ValueVariant.Generator/ValueVariantGenerator.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.ValueVariant;
 
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
@@ -44,7 +43,7 @@ public void Execute(GeneratorExecutionContext context)
             if (attr is null) return (symbol, attr, itf: default(INamedTypeSymbol?));
 
             var itf = symbol.Interfaces
-                .SingleOrDefault(e => e.ToString().StartsWith("System.ValueVariant.IValueVariant<") && e.TypeArguments.Length >= 2);
+                .SingleOrDefault(e => e.ToString().StartsWith("ValueVariant.IValueVariant<") && e.TypeArguments.Length >= 2);
 
             return (symbol, attr, itf);
         }).Where(e => e.attr is not null && e.itf is not null).Select(e => (e.symbol, e.attr!, e.itf!));

ValueVariant.Generator/ValueVariantTemplate.partial.cs

@@ -1,6 +1,5 @@
 
 using System.Linq;
-using System.ValueVariant;
 
 namespace ValueVariant.Generator;
 

ValueVariant.Generator/ValueVariantTemplate.tt

@@ -4,7 +4,7 @@
 <#@ import namespace="System.Linq" #>
 <#@ import namespace="System.Text" #>
 <#@ import namespace="System.Collections.Generic" #>
-<#@ import namespace="System.ValueVariant" #>
+<#@ import namespace="ValueVariant" #>
 <#@ include file="../Const.t4" #>
 // <auto-generated>
 // THIS (.cs) FILE IS GENERATED BY ValueVariant.Generator. DO NOT CHANGE IT.
@@ -27,7 +27,7 @@ using System.Diagnostics.CodeAnalysis;
 
 namespace <#= Namespace #>
 {
-    using V2 = global::System.ValueVariant;
+    using V2 = global::ValueVariant;
 
     using T = global::<#= FullName #>;
 
@@ -155,12 +155,32 @@ namespace <#= Namespace #>
         public TR Accept<TA1, TR>(V2.IValueVariantGenericFuncVisitor<TA1, TR> visitor, TA1 arg1)
             => V2.Details.ValueVariant<<#= Join(1, Count, e => $"T{e}") #>>.AcceptGenericFuncVisitor<T, V2.IValueVariantGenericFuncVisitor<TA1, TR>, TA1, TR>(this, visitor, arg1);
 
-        public readonly struct DefaultConverter : IFuncVisitor<T>
+        public class DefaultConverter : IFuncVisitor<T>
         {
+            public static DefaultConverter Instance { get; } = new DefaultConverter();
+
 <# for (var i = 1; i <= Count; ++i ) { #>
             public T Visit(in T<#= i #> value) => value;
 <# } #>
         }
+
+        public class DefaultConverter<TEx1> : DefaultConverter, V2.IValueVariantFuncVisitor<TEx1, T>
+            where TEx1 : unmanaged
+        {
+            public static new DefaultConverter<TEx1> Instance { get; } = new DefaultConverter<TEx1>();
+
+            public T Visit(in TEx1 value) => default;
+        }
+<# for (var i = 2; i <= 4; ++i ) { #>
+
+        public class DefaultConverter<<#= Join(1, i, e => $"TEx{e}") #>> : DefaultConverter<<#= Join(1, i - 1, e => $"TEx{e}") #>>, V2.IValueVariantFuncVisitor<TEx<#= i #>, T>
+            <#= string.Join(" ", Range(1, i, e => $"where TEx{e}: unmanaged")) #>
+        {
+            public static new DefaultConverter<<#= Join(1, i, e => $"TEx{e}") #>> Instance { get; } = new DefaultConverter<<#= Join(1, i, e => $"TEx{e}") #>>();
+
+            public T Visit(in TEx<#= i #> value) => default;
+        }
+<# } #>
 <# if (Options.HasFlag(ValueVariantGenerateOptions.MessagePackFormatter)) { #>
 
         private sealed class MessagePackFormatter : IMessagePackFormatter<T>

ValueVariant.Test/TestVariant.cs

@@ -1,25 +1,46 @@
 using System;
 
-using System.ValueVariant;
-
 using Variant.Test;
 
 namespace ValueVariant.Test;
 
 [ValueVariant(ValueVariantGenerateOptions.MessagePackFormatter)]
-public readonly partial struct TestVariant : IValueVariant<TestVariant, int, TestStruct<Guid>, DateTime> { }
+public readonly partial struct TestVariant : IValueVariant<TestVariant, int, TestStruct<Guid>, DateTime>
+{
+    public static explicit operator TestVariant(TestVariant2 value)
+            => value.TryCast(out var result) ? result : throw new InvalidCastException();
+
+    public readonly bool TryCast(out TestVariant2 result)
+    {
+        if (this == default) { result = default; return true; }
+        this.Accept(TestVariant2.DefaultConverter.Instance, out result);
+        return result != default;
+    }
+}
 
-public readonly struct TestVariantVisitor : TestVariant.IFuncVisitor<Type>
+public readonly struct TestVariantVisitor : TestVariant.IFuncVisitor<Type>, TestVariant2.IFuncVisitor<Type>
 {
-    public Type Visit(in int value)
-        => typeof(int);
+    public Type Visit(in int value) => typeof(int);
+
+    public Type Visit(in TestStruct<Guid> value) => typeof(TestStruct<Guid>);
 
-    public Type Visit(in TestStruct<Guid> value)
-        => typeof(TestStruct<Guid>);
+    public Type Visit(in DateTime value) => typeof(DateTime);
 
-    public Type Visit(in DateTime value)
-        => typeof(DateTime);
+    public Type Visit(in long value) => typeof(long);
+
+    public Type Visit(in bool value) => typeof(bool);
 }
 
 [ValueVariant]
-public readonly partial struct TestVariant2 : IValueVariant<TestVariant2, TestStruct<Guid>, DateTime, int> { }
+public readonly partial struct TestVariant2 : IValueVariant<TestVariant2, TestStruct<Guid>, DateTime, int, long, bool>
+{
+    public static explicit operator TestVariant2(TestVariant value)
+        => value.TryCast(out var result) ? result : throw new InvalidCastException();
+
+    public readonly bool TryCast(out TestVariant result)
+    {
+        if (this == default) { result = default; return true; }
+        this.Accept(TestVariant.DefaultConverter<long, bool>.Instance, out result);
+        return result != default;
+    }
+}

ValueVariant.Test/UnitTest1.cs

@@ -1,5 +1,4 @@
 using System;
-using System.ValueVariant;
 
 using MessagePack;
 
@@ -20,21 +19,25 @@ public void Test1()
 
             v = default(int);
             Assert.Equal(typeof(int), v.Accept(new TestVariantVisitor()));
-            v.Accept(new TestVariant2.DefaultConverter(), out v2);
+            v2 = (TestVariant2)v;
             v2.Accept(new TestVariantVisitor(), out type);
             Assert.Equal(typeof(int), type);
 
             v = default(TestStruct<Guid>);
             Assert.Equal(typeof(TestStruct<Guid>), v.Accept(new TestVariantVisitor()));
-            v.Accept(new TestVariant2.DefaultConverter(), out v2);
+            v2 = (TestVariant2)v;
             v2.Accept(new TestVariantVisitor(), out type);
             Assert.Equal(typeof(TestStruct<Guid>), type);
 
             v = default(DateTime);
             Assert.Equal(typeof(DateTime), v.Accept(new TestVariantVisitor()));
-            v.Accept(new TestVariant2.DefaultConverter(), out v2);
+            v2 = (TestVariant2)v;
             v2.Accept(new TestVariantVisitor(), out type);
             Assert.Equal(typeof(DateTime), type);
+
+            v2 = default(long);
+            Assert.Equal(typeof(long), v2.Accept(new TestVariantVisitor()));
+            Assert.Throws<InvalidCastException>(() => (TestVariant)v2);
         }
 
         [Fact]

ValueVariant.Test/ValueVariant.Test.csproj

@@ -7,13 +7,13 @@
 
   <ItemGroup>
     <PackageReference Include="MessagePack" Version="2.3.85" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.2.0" />
-    <PackageReference Include="xunit" Version="2.4.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.4.0" />
+    <PackageReference Include="xunit" Version="2.4.2" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
-    <PackageReference Include="coverlet.collector" Version="3.1.2">
+    <PackageReference Include="coverlet.collector" Version="3.2.0">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>

ValueVariant/Details/IValueVariant.cs

@@ -1,7 +1,7 @@
 
 using System.Runtime.CompilerServices;
 
-namespace System.ValueVariant.Details;
+namespace ValueVariant.Details;
 
 public interface IValueVariant
 {

ValueVariant/Details/IValueVariantIndex.tt

@@ -12,7 +12,7 @@
 
 using System.Runtime.CompilerServices;
 
-namespace System.ValueVariant.Details;
+namespace ValueVariant.Details;
 <# for (var i = 1; i <= MaxTypeParam; ++i) { #>
 
 public interface IValueVariantIndex<#= i #><T>: IValueVariant where T: unmanaged

ValueVariant/Details/IValueVariantT.tt

@@ -10,7 +10,7 @@
 // </auto-generated>
 #nullable enable
 
-namespace System.ValueVariant.Details;
+namespace ValueVariant.Details;
 <# for (var i = 1; i <= MaxTypeParam; ++i) { #>
 
 public interface IValueVariant<<#= Join(1, i, e => $"T{e}") #>>:

ValueVariant/Details/Throw.cs

@@ -1,9 +1,10 @@
+using System;
 
 #if NETSTANDARD2_1_OR_GREATER
 using System.Diagnostics.CodeAnalysis;
 #endif
 
-namespace System.ValueVariant.Details;
+namespace ValueVariant.Details;
 
 internal static class Throw
 {

ValueVariant/Details/ValueVariantT.ActionVisitor.tt

@@ -12,9 +12,9 @@
 
 using System.Runtime.CompilerServices;
 
-using V2 = System.ValueVariant;
+using V2 = ValueVariant;
 
-namespace System.ValueVariant.Details;
+namespace ValueVariant.Details;
 <# for (var i = 1; i <= MaxTypeParam; ++i) { #>
 
 partial class ValueVariant<<#= Join(1, i, e => $"T{e}") #>>

ValueVariant/Details/ValueVariantT.FuncVisitor.tt

@@ -12,9 +12,9 @@
 
 using System.Runtime.CompilerServices;
 
-using V2 = System.ValueVariant;
+using V2 = ValueVariant;
 
-namespace System.ValueVariant.Details;
+namespace ValueVariant.Details;
 <# for (var i = 1; i <= MaxTypeParam; ++i) { #>
 
 partial class ValueVariant<<#= Join(1, i, e => $"T{e}") #>>

ValueVariant/Details/ValueVariantT.GenericActionVisitor.tt

@@ -12,9 +12,9 @@
 
 using System.Runtime.CompilerServices;
 
-using V2 = System.ValueVariant;
+using V2 = ValueVariant;
 
-namespace System.ValueVariant.Details;
+namespace ValueVariant.Details;
 <# for (var i = 1; i <= MaxTypeParam; ++i) { #>
 
 partial class ValueVariant<<#= Join(1, i, e => $"T{e}") #>>

ValueVariant/Details/ValueVariantT.GenericFuncVisitor.tt

@@ -12,9 +12,9 @@
 
 using System.Runtime.CompilerServices;
 
-using V2 = System.ValueVariant;
+using V2 = ValueVariant;
 
-namespace System.ValueVariant.Details;
+namespace ValueVariant.Details;
 <# for (var i = 1; i <= MaxTypeParam; ++i) { #>
 
 partial class ValueVariant<<#= Join(1, i, e => $"T{e}") #>>

ValueVariant/Details/ValueVariantT.IEquatable.tt

@@ -10,12 +10,13 @@
 // </auto-generated>
 #nullable enable
 
+using System;
 using System.Collections.Generic;
 using System.Runtime.CompilerServices;
 
-using V2 = System.ValueVariant;
+using V2 = ValueVariant;
 
-namespace System.ValueVariant.Details;
+namespace ValueVariant.Details;
 <# for (var i = 1; i <= MaxTypeParam; ++i) { #>
 
 partial class ValueVariant<<#= Join(1, i, e => $"T{e}") #>>

ValueVariant/Details/ValueVariantT.tt

@@ -10,7 +10,7 @@
 // </auto-generated>
 #nullable enable
 
-namespace System.ValueVariant.Details;
+namespace ValueVariant.Details;
 <# for (var i = 1; i <= MaxTypeParam; ++i) { #>
 
 public static partial class ValueVariant<<#= Join(1, i, e => $"T{e}") #>> <#= string.Join(" ", Range(1, i, e => $"where T{e}: unmanaged")) #> { }

ValueVariant/IValueVariantT.tt

@@ -10,7 +10,7 @@
 // </auto-generated>
 #nullable enable
 
-namespace System.ValueVariant;
+namespace ValueVariant;
 <# for (var i = 1; i <= MaxTypeParam; ++i) { #>
 
 public interface IValueVariant<T, <#= Join(1, i, e => $"T{e}") #>>:

ValueVariant/IValueVariantVisitor.cs

@@ -1,5 +1,5 @@
 
-namespace System.ValueVariant;
+namespace ValueVariant;
 
 public interface IValueVariantActionVisitor<T> where T: unmanaged
 {

ValueVariant/ValueVariant.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0;netstandard2.1</TargetFrameworks>
-    <RootNamespace>System.ValueVariant</RootNamespace>
+    <RootNamespace>ValueVariant</RootNamespace>
     <IsPackable>true</IsPackable>
   </PropertyGroup>
 

ValueVariant/ValueVariantAttribute.cs

@@ -1,5 +1,6 @@
+using System;
 
-namespace System.ValueVariant
+namespace ValueVariant
 {
     [Flags]
     public enum ValueVariantGenerateOptions