Add DateTime operators to SYSTEMTIME and implement IEquatable

Add Tests for Template structs

Author: elachlan

src/Microsoft.Windows.CsWin32/Generator.cs

@@ -3726,6 +3726,7 @@ private StructDeclarationSyntax DeclareStruct(TypeDefinitionHandle typeDefHandle
         {
             case "RECT":
             case "SIZE":
+            case "SYSTEMTIME":
                 members.AddRange(this.ExtractMembersFromTemplate(name.Identifier.ValueText));
                 break;
             default:

src/Microsoft.Windows.CsWin32/templates/SYSTEMTIME.cs

@@ -0,0 +1,75 @@
+partial struct SYSTEMTIME
+	: IEquatable<SYSTEMTIME>
+{
+	public bool Equals(SYSTEMTIME other)
+	{
+		return this.wYear == other.wYear &&
+			   this.wMonth == other.wMonth &&
+			   this.wDayOfWeek == other.wDayOfWeek &&
+			   this.wDay == other.wDay &&
+			   this.wHour == other.wHour &&
+			   this.wMinute == other.wMinute &&
+			   this.wSecond == other.wSecond &&
+			   this.wMilliseconds == other.wMilliseconds;
+	}
+
+	public override bool Equals(object obj) => obj is SYSTEMTIME other && this.Equals(other);
+	public override int GetHashCode() => (this.wYear, this.wMonth, this.wDayOfWeek, this.wDay, this.wHour, this.wMinute, this.wSecond, this.wMilliseconds).GetHashCode();
+
+	public static bool operator ==(SYSTEMTIME d1, SYSTEMTIME d2)
+	{
+		return d1.wYear == d2.wYear &&
+			   d1.wMonth == d2.wMonth &&
+			   d1.wDayOfWeek == d2.wDayOfWeek &&
+			   d1.wDay == d2.wDay &&
+			   d1.wHour == d2.wHour &&
+			   d1.wMinute == d2.wMinute &&
+			   d1.wSecond == d2.wSecond &&
+			   d1.wMilliseconds == d2.wMilliseconds;
+	}
+
+	public static bool operator !=(SYSTEMTIME d1, SYSTEMTIME d2)
+	{
+		return d1.wYear != d2.wYear &&
+			   d1.wMonth != d2.wMonth &&
+			   d1.wDayOfWeek != d2.wDayOfWeek &&
+			   d1.wDay != d2.wDay &&
+			   d1.wHour != d2.wHour &&
+			   d1.wMinute != d2.wMinute &&
+			   d1.wSecond != d2.wSecond &&
+			   d1.wMilliseconds != d2.wMilliseconds;
+	}
+
+	public static implicit operator global::System.DateTime(SYSTEMTIME sysTime)
+	{
+		if (sysTime == default(SYSTEMTIME) || sysTime.wYear <= 0 || sysTime.wMonth <= 0 || sysTime.wDay <= 0)
+		{
+			return default;
+		}
+
+		// DateTime gets DayOfWeek automatically
+		return new global::System.DateTime(sysTime.wYear,
+			sysTime.wMonth, sysTime.wDay, sysTime.wHour,
+			sysTime.wMinute, sysTime.wSecond, sysTime.wMilliseconds);
+	}
+
+	public static implicit operator SYSTEMTIME(global::System.DateTime time)
+	{
+		if (time == default)
+		{
+			return default;
+		}
+
+		return new SYSTEMTIME
+		{
+			wYear = checked((ushort)time.Year),
+			wMonth = checked((ushort)time.Month),
+			wDayOfWeek = checked((ushort)time.DayOfWeek),
+			wDay = checked((ushort)time.Day),
+			wHour = checked((ushort)time.Hour),
+			wMinute = checked((ushort)time.Minute),
+			wSecond = checked((ushort)time.Second),
+			wMilliseconds = checked((ushort)time.Millisecond)
+		};
+	}
+}

test/Microsoft.Windows.CsWin32.Tests/GeneratorTests.cs

@@ -605,6 +605,24 @@ public void HandleStructsHaveStaticNullMember(string handleName)
         this.AssertGeneratedMember(handleName, "Null", $"internal static {handleName} Null => default;");
     }
 
+    [Theory]
+    [InlineData("BOOL")]
+    [InlineData("BOOLEAN")]
+    [InlineData("HRESULT")]
+    [InlineData("NTSTATUS")]
+    [InlineData("PCSTR")]
+    [InlineData("PCWSTR")]
+    [InlineData("RECT")]
+    [InlineData("SIZE")]
+    [InlineData("SYSTEMTIME")]
+    public void TemplateAPIsGenerate(string handleType)
+    {
+        this.generator = this.CreateGenerator();
+        Assert.True(this.generator.TryGenerate(handleType, CancellationToken.None));
+        this.CollectGeneratedCode(this.generator);
+        this.AssertNoDiagnostics();
+    }
+
     [Theory]
     [InlineData("HANDLE")]
     [InlineData("HGDIOBJ")]