C# 11 goodies

build/Shims.cs

@@ -5,7 +5,6 @@
 using System.Xml.Linq;
 using ICSharpCode.SharpZipLib.GZip;
 using ICSharpCode.SharpZipLib.Tar;
-using Nuke.Common;
 using Nuke.Common.CI;
 using Nuke.Common.CI.AppVeyor;
 using Nuke.Common.CI.GitHubActions;

build/common.props

@@ -14,7 +14,7 @@
     <CLSCompliant>false</CLSCompliant>
     <ComVisible>false</ComVisible>
 
-    <LangVersion>9</LangVersion>
+    <LangVersion>11</LangVersion>
 
     <Major>2</Major>
     <Minor>4</Minor>

samples/NetVips.Samples/Program.cs

@@ -33,7 +33,7 @@ static void Main(string[] args)
             string input;
             do
             {
-                string[] sampleArgs = Array.Empty<string>();
+                var sampleArgs = Array.Empty<string>();
                 if (args.Length > 0)
                 {
                     var sampleId = Samples.Select((value, index) => new { Index = index + 1, value.Name })

samples/NetVips.Samples/Samples/CaptchaGenerator.cs

@@ -65,7 +65,7 @@ public void Execute(string[] args)
                 using var wobble = Wobble(similarity);
 
                 // random colour
-                var colour = Enumerable.Range(1, 3).Select(i => random.Next(0, 255)).ToArray();
+                var colour = Enumerable.Range(1, 3).Select(_ => random.Next(0, 255)).ToArray();
                 using var ifthenelse = wobble.Ifthenelse(colour, 0, blend: true);
 
                 // tag as 9-bit srgb
@@ -101,10 +101,10 @@ public void Execute(string[] args)
                 textLayer = textLayer.Bandjoin(alpha);
             }
 
-            //  make a white background with random speckles
+            // make a white background with random speckles
             using var speckles = Image.Gaussnoise(textLayer.Width, textLayer.Height, mean: 400, sigma: 200);
             using var background = Enumerable.Range(1, 2).Aggregate(speckles,
-                (a, b) =>
+                (a, _) =>
                 {
                     using (a)
                     {

samples/NetVips.Samples/Samples/GenerateImageClass.cs

@@ -12,7 +12,7 @@ public class GenerateImageClass : ISample
         public string Name => "Generate image class";
         public string Category => "Internal";
 
-        private readonly Dictionary<IntPtr, string> _gTypeToCSharpDict = new Dictionary<IntPtr, string>
+        private readonly Dictionary<nint, string> _gTypeToCSharpDict = new()
         {
             {GValue.GBoolType, "bool"},
             {GValue.GIntType, "int"},
@@ -35,12 +35,12 @@ public class GenerateImageClass : ISample
         /// <summary>
         /// The fundamental type for VipsFailOn. See <see cref="Enums.FailOn"/>.
         /// </summary>
-        public static readonly IntPtr FailOnType = NetVips.TypeFromName("VipsFailOn");
+        public static readonly nint FailOnType = NetVips.TypeFromName("VipsFailOn");
 
         /// <summary>
         /// The fundamental type for VipsForeignKeep. See <see cref="Enums.ForeignKeep"/>.
         /// </summary>
-        public static readonly IntPtr ForeignKeepType = NetVips.TypeFromName("VipsForeignKeep");
+        public static readonly nint ForeignKeepType = NetVips.TypeFromName("VipsForeignKeep");
 
         public GenerateImageClass()
         {
@@ -119,7 +119,7 @@ public GenerateImageClass()
         /// <param name="name">The GType identifier.</param>
         /// <param name="gtype">The GType to map.</param>
         /// <returns>The C# type we use to represent it.</returns>
-        private string GTypeToCSharp(string name, IntPtr gtype)
+        private string GTypeToCSharp(string name, nint gtype)
         {
             if (_gTypeToCSharpDict.ContainsKey(gtype))
             {
@@ -190,29 +190,22 @@ string SafeIdentifier(string name) =>
 
             string SafeCast(string type, string name = "result")
             {
-                switch (type)
-                {
-                    case "GObject":
-                    case "Image":
-                    case "int[]":
-                    case "double[]":
-                    case "byte[]":
-                    case "Image[]":
-                    case "object[]":
-                        return $" as {type};";
-                    case "bool":
-                        return $" is {type} {name} && {name};";
-                    case "int":
-                        return $" is {type} {name} ? {name} : 0;";
-                    case "ulong":
-                        return $" is {type} {name} ? {name} : 0ul;";
-                    case "double":
-                        return $" is {type} {name} ? {name} : 0d;";
-                    case "string":
-                        return $" is {type} {name} ? {name} : null;";
-                    default:
-                        return ";";
-                }
+                return type switch
+                {
+                    "GObject" => $" as {type};",
+                    "Image" => $" as {type};",
+                    "int[]" => $" as {type};",
+                    "double[]" => $" as {type};",
+                    "byte[]" => $" as {type};",
+                    "Image[]" => $" as {type};",
+                    "object[]" => $" as {type};",
+                    "bool" => $" is {type} {name} && {name};",
+                    "int" => $" is {type} {name} ? {name} : 0;",
+                    "ulong" => $" is {type} {name} ? {name} : 0ul;",
+                    "double" => $" is {type} {name} ? {name} : 0d;",
+                    "string" => $" is {type} {name} ? {name} : null;",
+                    _ => ";"
+                };
             }
 
             string ExplicitCast(string type)
@@ -226,26 +219,23 @@ string ExplicitCast(string type)
 
             string ToNullable(string type, string name)
             {
-                switch (type)
+                return type switch
                 {
-                    case "Image[]":
-                    case "object[]":
-                    case "int[]":
-                    case "double[]":
-                    case "byte[]":
-                    case "GObject":
-                    case "Image":
-                    case "string":
-                        return $"{type} {name} = null";
-                    case "bool":
-                    case "int":
-                    case "ulong":
-                    case "double":
-                    case { } enumString when enumString.StartsWith("Enums."):
-                        return $"{type}? {name} = null";
-                    default:
-                        throw new Exception($"Unsupported type: {type}");
-                }
+                    "Image[]" => $"{type} {name} = null",
+                    "object[]" => $"{type} {name} = null",
+                    "int[]" => $"{type} {name} = null",
+                    "double[]" => $"{type} {name} = null",
+                    "byte[]" => $"{type} {name} = null",
+                    "GObject" => $"{type} {name} = null",
+                    "Image" => $"{type} {name} = null",
+                    "string" => $"{type} {name} = null",
+                    "bool" => $"{type}? {name} = null",
+                    "int" => $"{type}? {name} = null",
+                    "ulong" => $"{type}? {name} = null",
+                    "double" => $"{type}? {name} = null",
+                    { } enumString when enumString.StartsWith("Enums.") => $"{type}? {name} = null",
+                    _ => throw new Exception($"Unsupported type: {type}")
+                };
             }
 
             var result = new StringBuilder($"{indent}/// <summary>\n");
@@ -555,7 +545,7 @@ string ToCref(string name) =>
             result.Append($"{indent}}}")
                 .AppendLine();
 
-            var firstArgType = requiredInput.Length > 0 ? op.GetTypeOf(requiredInput[0].Name) : IntPtr.Zero;
+            nint firstArgType = requiredInput.Length > 0 ? op.GetTypeOf(requiredInput[0].Name) : IntPtr.Zero;
 
             // Create stream overload if necessary
             if (firstArgType == GValue.SourceType || firstArgType == GValue.TargetType)

samples/NetVips.Samples/Samples/GenerateImageOperators.cs

@@ -12,12 +12,14 @@ public class GenerateImageOperators : ISample
 
         private const string Indent = "        ";
 
-        private readonly string _docstring = $@"{Indent}/// <summary>
-{Indent}/// This operation {{0}}.
-{Indent}/// </summary>
-{Indent}/// <param name=""left"">{{1}}.</param>
-{Indent}/// <param name=""right"">{{2}}.</param>
-{Indent}/// <returns>A new <see cref=""Image""/>.</returns>";
+        private readonly string _docstring = $$"""
+                                               {{Indent}}/// <summary>
+                                               {{Indent}}/// This operation {0}.
+                                               {{Indent}}/// </summary>
+                                               {{Indent}}/// <param name="left">{1}.</param>
+                                               {{Indent}}/// <param name="right">{2}.</param>
+                                               {{Indent}}/// <returns>A new <see cref="Image"/>.</returns>
+                                               """;
 
         /// <summary>
         /// Make a C#-style docstring + operator overload.

samples/NetVips.Samples/Samples/NetworkStream.cs

@@ -3,7 +3,6 @@ namespace NetVips.Samples
     using System;
     using System.IO;
     using System.Net.Http;
-    using System.Threading.Tasks;
 
     public class NetworkStream : ISample
     {
@@ -39,7 +38,7 @@ public async void Execute(string[] args)
             using var image = Image.NewFromSource(source, access: Enums.Access.Sequential);
             Console.WriteLine(image.ToString());
 
-            using var output = File.OpenWrite("stream-network.jpg");
+            await using var output = File.OpenWrite("stream-network.jpg");
             image.WriteToStream(output, ".jpg");
 
             Console.WriteLine("See stream-network.jpg");

samples/NetVips.Samples/Samples/OnePointMosaic.cs

@@ -22,7 +22,7 @@ public Point(int x, int y)
             }
         }
 
-        public List<string> Images = new List<string>
+        public List<string> Images = new()
         {
             "images/cd1.1.jpg",
             "images/cd1.2.jpg",
@@ -34,7 +34,7 @@ public Point(int x, int y)
             "images/cd4.2.jpg"
         };
 
-        public List<Point> HorizontalMarks = new List<Point>
+        public List<Point> HorizontalMarks = new()
         {
             new Point(489, 140),
             new Point(66, 141),
@@ -46,7 +46,7 @@ public Point(int x, int y)
             new Point(40, 57)
         };
 
-        public List<Point> VerticalMarks = new List<Point>
+        public List<Point> VerticalMarks = new()
         {
             new Point(364, 346),
             new Point(388, 44),

samples/NetVips.Samples/Samples/PostClose.cs

@@ -19,7 +19,7 @@ public void Execute(string[] args)
             // Avoid reusing the image after subsequent use
             Cache.Max = 0;
 
-            Action action = OnPostClose;
+            var action = OnPostClose;
 
             var im = Image.NewFromFile(Filename, access: Enums.Access.Sequential);
             im.OnPostClose += action;

samples/NetVips.Samples/Samples/Progress.cs

@@ -24,7 +24,7 @@ public void Execute(string[] args)
             test.SignalConnect(Enums.Signals.Eval, EvalHandler);
             test.SignalConnect(Enums.Signals.PostEval, PostEvalHandler);
 
-            var avg = test.Avg();
+            _ = test.Avg();
         }
 
         private void ProgressPrint(Enums.Signals signal, VipsProgress progress)

samples/NetVips.Samples/Samples/RandomCropper.cs

@@ -16,7 +16,7 @@ public class RandomCropper : ISample
 
         public const string Filename = "images/equus_quagga.jpg";
 
-        public static readonly Random Rnd = new Random();
+        public static readonly Random Rnd = new();
 
         public Image RandomCrop(Image image, int tileSize)
         {

src/NetVips.Extensions/BitmapConverter.cs

@@ -21,30 +21,27 @@ public static class BitmapConverter
         /// <returns>The number of bands.</returns>
         private static int GuessBands(PixelFormat pixelFormat)
         {
-            switch (pixelFormat)
+            return pixelFormat switch
             {
-                case PixelFormat.Format8bppIndexed:
+                PixelFormat.Format8bppIndexed =>
                     /* Note: Maplut below will create a 3-band image */
-                    return 1;
+                    1,
                 /*case PixelFormat.Format16bppGrayScale:
                     return 2;*/
                 /*case PixelFormat.Format1bppIndexed:*/
                 /*case PixelFormat.Format4bppIndexed:*/
                 /*case PixelFormat.Format16bppRgb555:*/
                 /*case PixelFormat.Format16bppRgb565:*/
-                case PixelFormat.Format24bppRgb:
+                PixelFormat.Format24bppRgb => 3,
                 /*case PixelFormat.Format32bppRgb:*/
-                case PixelFormat.Format48bppRgb:
-                    return 3;
+                PixelFormat.Format48bppRgb => 3,
                 /*case PixelFormat.Format16bppArgb1555:*/
-                case PixelFormat.Format32bppArgb:
-                case PixelFormat.Format32bppPArgb:
-                case PixelFormat.Format64bppArgb:
-                case PixelFormat.Format64bppPArgb:
-                    return 4;
-                default:
-                    throw new NotImplementedException($"GuessBands({pixelFormat}) is not yet implemented.");
-            }
+                PixelFormat.Format32bppArgb => 4,
+                PixelFormat.Format32bppPArgb => 4,
+                PixelFormat.Format64bppArgb => 4,
+                PixelFormat.Format64bppPArgb => 4,
+                _ => throw new NotImplementedException($"GuessBands({pixelFormat}) is not yet implemented.")
+            };
         }
 
         /// <summary>
@@ -57,27 +54,24 @@ private static int GuessBands(PixelFormat pixelFormat)
         /// <returns>The <see cref="Enums.BandFormat"/>.</returns>
         private static Enums.BandFormat GuessBandFormat(PixelFormat pixelFormat)
         {
-            switch (pixelFormat)
+            return pixelFormat switch
             {
                 /*case PixelFormat.Format1bppIndexed:*/
                 /*case PixelFormat.Format4bppIndexed:*/
-                case PixelFormat.Format8bppIndexed:
+                PixelFormat.Format8bppIndexed => Enums.BandFormat.Uchar,
                 /*case PixelFormat.Format16bppGrayScale:*/
                 /*case PixelFormat.Format16bppRgb555:*/
                 /*case PixelFormat.Format16bppRgb565:*/
-                case PixelFormat.Format24bppRgb:
+                PixelFormat.Format24bppRgb => Enums.BandFormat.Uchar,
                 /*case PixelFormat.Format32bppRgb:*/
                 /*case PixelFormat.Format16bppArgb1555:*/
-                case PixelFormat.Format32bppArgb:
-                case PixelFormat.Format32bppPArgb:
-                    return Enums.BandFormat.Uchar;
-                case PixelFormat.Format48bppRgb:
-                case PixelFormat.Format64bppArgb:
-                case PixelFormat.Format64bppPArgb:
-                    return Enums.BandFormat.Ushort;
-                default:
-                    throw new NotImplementedException($"GuessBandFormat({pixelFormat}) is not yet implemented.");
-            }
+                PixelFormat.Format32bppArgb => Enums.BandFormat.Uchar,
+                PixelFormat.Format32bppPArgb => Enums.BandFormat.Uchar,
+                PixelFormat.Format48bppRgb => Enums.BandFormat.Ushort,
+                PixelFormat.Format64bppArgb => Enums.BandFormat.Ushort,
+                PixelFormat.Format64bppPArgb => Enums.BandFormat.Ushort,
+                _ => throw new NotImplementedException($"GuessBandFormat({pixelFormat}) is not yet implemented.")
+            };
         }
 
         /// <summary>

src/NetVips/Cache.cs

@@ -21,7 +21,7 @@ public static int Max
         /// </summary>
         public static ulong MaxMem
         {
-            get => (ulong) Vips.CacheGetMaxMem();
+            get => Vips.CacheGetMaxMem();
             set => Vips.CacheSetMaxMem(value);
         }
 

src/NetVips/ExtensionMethods.cs

@@ -104,7 +104,7 @@ internal static object[] PrependImage<T>(this T[] args, Image image)
         /// <param name="freePtr">If set to <see langword="true"/>, free the GLib string.</param>
         /// <param name="size">Size of the GLib string, use 0 to read until the null character.</param>
         /// <returns>The managed string.</returns>
-        internal static string ToUtf8String(this IntPtr utf8Str, bool freePtr = false, int size = 0)
+        internal static string ToUtf8String(this nint utf8Str, bool freePtr = false, int size = 0)
         {
             if (utf8Str == IntPtr.Zero)
             {