Annotate readonly structs

src/ImageSharp/ColorSpaces/CieLab.cs

@@ -12,7 +12,7 @@ namespace SixLabors.ImageSharp.ColorSpaces
     /// Represents a CIE L*a*b* 1976 color.
     /// <see href="https://en.wikipedia.org/wiki/Lab_color_space"/>
     /// </summary>
-    internal struct CieLab : IColorVector, IEquatable<CieLab>, IAlmostEquatable<CieLab, float>
+    internal readonly struct CieLab : IColorVector, IEquatable<CieLab>, IAlmostEquatable<CieLab, float>
     {
         /// <summary>
         /// D50 standard illuminant.

src/ImageSharp/ColorSpaces/CieLch.cs

@@ -12,7 +12,7 @@ namespace SixLabors.ImageSharp.ColorSpaces
     /// Represents the CIE L*C*h°, cylindrical form of the CIE L*a*b* 1976 color.
     /// <see href="https://en.wikipedia.org/wiki/Lab_color_space#Cylindrical_representation:_CIELCh_or_CIEHLC"/>
     /// </summary>
-    internal struct CieLch : IColorVector, IEquatable<CieLch>, IAlmostEquatable<CieLch, float>
+    internal readonly struct CieLch : IColorVector, IEquatable<CieLch>, IAlmostEquatable<CieLch, float>
     {
         /// <summary>
         /// D50 standard illuminant.

src/ImageSharp/ColorSpaces/CieLchuv.cs

@@ -12,7 +12,7 @@ namespace SixLabors.ImageSharp.ColorSpaces
     /// Represents the CIE L*C*h°, cylindrical form of the CIE L*u*v* 1976 color.
     /// <see href="https://en.wikipedia.org/wiki/Lab_color_space#Cylindrical_representation:_CieLchuv_or_CIEHLC"/>
     /// </summary>
-    internal struct CieLchuv : IColorVector, IEquatable<CieLchuv>, IAlmostEquatable<CieLchuv, float>
+    internal readonly struct CieLchuv : IColorVector, IEquatable<CieLchuv>, IAlmostEquatable<CieLchuv, float>
     {
         /// <summary>
         /// D50 standard illuminant.

src/ImageSharp/ColorSpaces/CieLuv.cs

@@ -14,7 +14,7 @@ namespace SixLabors.ImageSharp.ColorSpaces
     /// attempted perceptual uniformity
     /// <see href="https://en.wikipedia.org/wiki/CIELUV"/>
     /// </summary>
-    internal struct CieLuv : IColorVector, IEquatable<CieLuv>, IAlmostEquatable<CieLuv, float>
+    internal readonly struct CieLuv : IColorVector, IEquatable<CieLuv>, IAlmostEquatable<CieLuv, float>
     {
         /// <summary>
         /// D65 standard illuminant.

src/ImageSharp/ColorSpaces/CieXyChromaticityCoordinates.cs

@@ -12,7 +12,7 @@ namespace SixLabors.ImageSharp.ColorSpaces
     /// <summary>
     /// Represents the coordinates of CIEXY chromaticity space
     /// </summary>
-    internal struct CieXyChromaticityCoordinates : IEquatable<CieXyChromaticityCoordinates>, IAlmostEquatable<CieXyChromaticityCoordinates, float>
+    internal readonly struct CieXyChromaticityCoordinates : IEquatable<CieXyChromaticityCoordinates>, IAlmostEquatable<CieXyChromaticityCoordinates, float>
     {
         /// <summary>
         /// Represents a <see cref="CieXyChromaticityCoordinates"/> that has X, Y values set to zero.

src/ImageSharp/ColorSpaces/CieXyy.cs

@@ -12,7 +12,7 @@ namespace SixLabors.ImageSharp.ColorSpaces
     /// Represents an CIE xyY 1931 color
     /// <see href="https://en.wikipedia.org/wiki/CIE_1931_color_space#CIE_xy_chromaticity_diagram_and_the_CIE_xyY_color_space"/>
     /// </summary>
-    internal struct CieXyy : IColorVector, IEquatable<CieXyy>, IAlmostEquatable<CieXyy, float>
+    internal readonly struct CieXyy : IColorVector, IEquatable<CieXyy>, IAlmostEquatable<CieXyy, float>
     {
         /// <summary>
         /// Represents a <see cref="CieXyy"/> that has X, Y, and Y values set to zero.

src/ImageSharp/ColorSpaces/CieXyz.cs

@@ -12,7 +12,7 @@ namespace SixLabors.ImageSharp.ColorSpaces
     /// Represents an CIE XYZ 1931 color
     /// <see href="https://en.wikipedia.org/wiki/CIE_1931_color_space#Definition_of_the_CIE_XYZ_color_space"/>
     /// </summary>
-    internal struct CieXyz : IColorVector, IEquatable<CieXyz>, IAlmostEquatable<CieXyz, float>
+    internal readonly struct CieXyz : IColorVector, IEquatable<CieXyz>, IAlmostEquatable<CieXyz, float>
     {
         /// <summary>
         /// Represents a <see cref="CieXyz"/> that has X, Y, and Z values set to zero.

src/ImageSharp/ColorSpaces/Cmyk.cs

@@ -11,7 +11,7 @@ namespace SixLabors.ImageSharp.ColorSpaces
     /// <summary>
     /// Represents an CMYK (cyan, magenta, yellow, keyline) color.
     /// </summary>
-    internal struct Cmyk : IEquatable<Cmyk>, IAlmostEquatable<Cmyk, float>
+    internal readonly struct Cmyk : IEquatable<Cmyk>, IAlmostEquatable<Cmyk, float>
     {
         /// <summary>
         /// Represents a <see cref="Cmyk"/> that has C, M, Y, and K values set to zero.

src/ImageSharp/ColorSpaces/Conversion/Implementation/Rgb/RgbWorkingSpace.cs

@@ -6,7 +6,7 @@ namespace SixLabors.ImageSharp.ColorSpaces.Conversion.Implementation.RgbColorSap
     /// <summary>
     /// Trivial implementation of <see cref="IRgbWorkingSpace"/>
     /// </summary>
-    internal struct RgbWorkingSpace : IRgbWorkingSpace
+    internal readonly struct RgbWorkingSpace : IRgbWorkingSpace
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="RgbWorkingSpace"/> struct.

src/ImageSharp/ColorSpaces/Hsl.cs

@@ -11,7 +11,7 @@ namespace SixLabors.ImageSharp.ColorSpaces
     /// <summary>
     /// Represents a Hsl (hue, saturation, lightness) color.
     /// </summary>
-    internal struct Hsl : IColorVector, IEquatable<Hsl>, IAlmostEquatable<Hsl, float>
+    internal readonly struct Hsl : IColorVector, IEquatable<Hsl>, IAlmostEquatable<Hsl, float>
     {
         /// <summary>
         /// Represents a <see cref="Hsl"/> that has H, S, and L values set to zero.

src/ImageSharp/ColorSpaces/Hsv.cs

@@ -11,7 +11,7 @@ namespace SixLabors.ImageSharp.ColorSpaces
     /// <summary>
     /// Represents a HSV (hue, saturation, value) color. Also known as HSB (hue, saturation, brightness).
     /// </summary>
-    internal struct Hsv : IColorVector, IEquatable<Hsv>, IAlmostEquatable<Hsv, float>
+    internal readonly struct Hsv : IColorVector, IEquatable<Hsv>, IAlmostEquatable<Hsv, float>
     {
         /// <summary>
         /// Represents a <see cref="Hsv"/> that has H, S, and V values set to zero.

src/ImageSharp/ColorSpaces/HunterLab.cs

@@ -12,7 +12,7 @@ namespace SixLabors.ImageSharp.ColorSpaces
     /// Represents an Hunter LAB color.
     /// <see href="https://en.wikipedia.org/wiki/Lab_color_space"/>
     /// </summary>
-    internal struct HunterLab : IColorVector, IEquatable<HunterLab>, IAlmostEquatable<HunterLab, float>
+    internal readonly struct HunterLab : IColorVector, IEquatable<HunterLab>, IAlmostEquatable<HunterLab, float>
     {
         /// <summary>
         /// D50 standard illuminant.

src/ImageSharp/ColorSpaces/LinearRgb.cs

@@ -11,7 +11,7 @@ namespace SixLabors.ImageSharp.ColorSpaces
     /// <summary>
     /// Represents an linear Rgb color with specified <see cref="IRgbWorkingSpace"/> working space
     /// </summary>
-    internal struct LinearRgb : IColorVector, IEquatable<LinearRgb>, IAlmostEquatable<LinearRgb, float>
+    internal readonly struct LinearRgb : IColorVector, IEquatable<LinearRgb>, IAlmostEquatable<LinearRgb, float>
     {
         /// <summary>
         /// Represents a <see cref="LinearRgb"/> that has R, G, and B values set to zero.

src/ImageSharp/ColorSpaces/Lms.cs

@@ -13,7 +13,7 @@ namespace SixLabors.ImageSharp.ColorSpaces
     /// named after their responsivity (sensitivity) at long, medium and short wavelengths.
     /// <see href="https://en.wikipedia.org/wiki/LMS_color_space"/>
     /// </summary>
-    internal struct Lms : IColorVector, IEquatable<Lms>, IAlmostEquatable<Lms, float>
+    internal readonly struct Lms : IColorVector, IEquatable<Lms>, IAlmostEquatable<Lms, float>
     {
         /// <summary>
         /// Represents a <see cref="Lms"/> that has L, M, and S values set to zero.

src/ImageSharp/ColorSpaces/Rgb.cs

@@ -11,7 +11,7 @@ namespace SixLabors.ImageSharp.ColorSpaces
     /// <summary>
     /// Represents an RGB color with specified <see cref="IRgbWorkingSpace"/> working space
     /// </summary>
-    internal struct Rgb : IColorVector, IEquatable<Rgb>, IAlmostEquatable<Rgb, float>
+    internal readonly struct Rgb : IColorVector, IEquatable<Rgb>, IAlmostEquatable<Rgb, float>
     {
         /// <summary>
         /// Represents a <see cref="Rgb"/> that has R, G, and B values set to zero.

src/ImageSharp/ColorSpaces/YCbCr.cs

@@ -13,7 +13,7 @@ namespace SixLabors.ImageSharp.ColorSpaces
     /// <see href="http://en.wikipedia.org/wiki/YCbCr"/>
     /// <see href="http://www.ijg.org/files/T-REC-T.871-201105-I!!PDF-E.pdf"/>
     /// </summary>
-    internal struct YCbCr : IColorVector, IEquatable<YCbCr>, IAlmostEquatable<YCbCr, float>
+    internal readonly struct YCbCr : IColorVector, IEquatable<YCbCr>, IAlmostEquatable<YCbCr, float>
     {
         /// <summary>
         /// Represents a <see cref="YCbCr"/> that has Y, Cb, and Cr values set to zero.

src/ImageSharp/Formats/Gif/PackedField.cs

@@ -9,7 +9,7 @@ namespace SixLabors.ImageSharp.Formats.Gif
     /// Represents a byte of data in a GIF data stream which contains a number
     /// of data items.
     /// </summary>
-    internal struct PackedField : IEquatable<PackedField>
+    internal readonly struct PackedField : IEquatable<PackedField>
     {
         /// <summary>
         /// The individual bits representing the packed byte.

src/ImageSharp/Formats/Jpeg/Common/Decoder/AdobeMarker.cs

@@ -10,7 +10,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Common.Decoder
     /// Provides information about the Adobe marker segment.
     /// </summary>
     /// <remarks>See the included 5116.DCT.pdf file in the source for more information.</remarks>
-    internal struct AdobeMarker : IEquatable<AdobeMarker>
+    internal readonly struct AdobeMarker : IEquatable<AdobeMarker>
     {
         /// <summary>
         /// Gets the length of an adobe marker segment.

src/ImageSharp/Formats/Jpeg/Common/Decoder/JFifMarker.cs

@@ -9,7 +9,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Common.Decoder
     /// Provides information about the JFIF marker segment
     /// TODO: Thumbnail?
     /// </summary>
-    internal struct JFifMarker : IEquatable<JFifMarker>
+    internal readonly struct JFifMarker : IEquatable<JFifMarker>
     {
         /// <summary>
         /// Gets the length of an JFIF marker segment.

src/ImageSharp/Formats/Jpeg/GolangPort/Components/Decoder/InputProcessor.cs

@@ -5,8 +5,6 @@ using System;
 using System.IO;
 using System.Runtime.CompilerServices;
 
-using SixLabors.ImageSharp.Memory;
-
 namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort.Components.Decoder
 {
     /// <summary>

src/ImageSharp/Formats/Jpeg/GolangPort/Components/Encoder/HuffmanLut.cs

@@ -9,7 +9,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort.Components.Encoder
     /// codeword size in bits and the 24 least significant bits hold the codeword.
     /// The maximum codeword size is 16 bits.
     /// </summary>
-    internal struct HuffmanLut
+    internal readonly struct HuffmanLut
     {
         /// <summary>
         /// The compiled representations of theHuffmanSpec.

src/ImageSharp/Formats/Jpeg/GolangPort/Components/Encoder/HuffmanSpec.cs

@@ -6,7 +6,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.GolangPort.Components.Encoder
     /// <summary>
     ///     The Huffman encoding specifications.
     /// </summary>
-    internal struct HuffmanSpec
+    internal readonly struct HuffmanSpec
     {
 #pragma warning disable SA1118 // ParameterMustNotSpanMultipleLines
 

src/ImageSharp/Formats/Jpeg/PdfJsPort/Components/PdfJsYCbCrToRgbTables.cs

@@ -10,7 +10,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.PdfJsPort.Components
     /// Provides 8-bit lookup tables for converting from YCbCr to Rgb colorspace.
     /// Methods to build the tables are based on libjpeg implementation.
     /// </summary>
-    internal struct PdfJsYCbCrToRgbTables
+    internal readonly struct PdfJsYCbCrToRgbTables
     {
         /// <summary>
         /// The red red-chrominance table

src/ImageSharp/Memory/BufferArea{T}.cs

@@ -9,7 +9,7 @@ namespace SixLabors.ImageSharp.Memory
     /// This type is kind-of 2D Span, but it can live on heap.
     /// </summary>
     /// <typeparam name="T">The element type</typeparam>
-    internal struct BufferArea<T>
+    internal readonly struct BufferArea<T>
         where T : struct
     {
         /// <summary>

src/ImageSharp/MetaData/Profiles/ICC/Various/IccColorantTableEntry.cs

@@ -8,7 +8,7 @@ namespace SixLabors.ImageSharp.MetaData.Profiles.Icc
     /// <summary>
     /// Entry of ICC colorant table
     /// </summary>
-    internal struct IccColorantTableEntry : IEquatable<IccColorantTableEntry>
+    internal readonly struct IccColorantTableEntry : IEquatable<IccColorantTableEntry>
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="IccColorantTableEntry"/> struct.

src/ImageSharp/MetaData/Profiles/ICC/Various/IccNamedColor.cs

@@ -9,7 +9,7 @@ namespace SixLabors.ImageSharp.MetaData.Profiles.Icc
     /// <summary>
     /// A specific color with a name
     /// </summary>
-    internal struct IccNamedColor : IEquatable<IccNamedColor>
+    internal readonly struct IccNamedColor : IEquatable<IccNamedColor>
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="IccNamedColor"/> struct.

src/ImageSharp/MetaData/Profiles/ICC/Various/IccPositionNumber.cs

@@ -8,7 +8,7 @@ namespace SixLabors.ImageSharp.MetaData.Profiles.Icc
     /// <summary>
     /// Position of an object within an ICC profile
     /// </summary>
-    internal struct IccPositionNumber : IEquatable<IccPositionNumber>
+    internal readonly struct IccPositionNumber : IEquatable<IccPositionNumber>
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="IccPositionNumber"/> struct.

src/ImageSharp/MetaData/Profiles/ICC/Various/IccProfileId.cs

@@ -8,7 +8,7 @@ namespace SixLabors.ImageSharp.MetaData.Profiles.Icc
     /// <summary>
     /// ICC Profile ID
     /// </summary>
-    public struct IccProfileId : IEquatable<IccProfileId>
+    public readonly struct IccProfileId : IEquatable<IccProfileId>
     {
         /// <summary>
         /// A profile ID with all values set to zero

src/ImageSharp/MetaData/Profiles/ICC/Various/IccResponseNumber.cs

@@ -8,7 +8,7 @@ namespace SixLabors.ImageSharp.MetaData.Profiles.Icc
     /// <summary>
     /// Associates a normalized device code with a measurement value
     /// </summary>
-    internal struct IccResponseNumber : IEquatable<IccResponseNumber>
+    internal readonly struct IccResponseNumber : IEquatable<IccResponseNumber>
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="IccResponseNumber"/> struct.

src/ImageSharp/MetaData/Profiles/ICC/Various/IccScreeningChannel.cs

@@ -8,7 +8,7 @@ namespace SixLabors.ImageSharp.MetaData.Profiles.Icc
     /// <summary>
     /// A single channel of a <see cref="IccScreeningTagDataEntry"/>
     /// </summary>
-    internal struct IccScreeningChannel : IEquatable<IccScreeningChannel>
+    internal readonly struct IccScreeningChannel : IEquatable<IccScreeningChannel>
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="IccScreeningChannel"/> struct.

src/ImageSharp/MetaData/Profiles/ICC/Various/IccTagTableEntry.cs

@@ -8,7 +8,7 @@ namespace SixLabors.ImageSharp.MetaData.Profiles.Icc
     /// <summary>
     /// Entry of ICC tag table
     /// </summary>
-    internal struct IccTagTableEntry : IEquatable<IccTagTableEntry>
+    internal readonly struct IccTagTableEntry : IEquatable<IccTagTableEntry>
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="IccTagTableEntry"/> struct.

src/ImageSharp/Numerics/ValueSize.cs

@@ -9,7 +9,7 @@ namespace SixLabors.ImageSharp
     /// <summary>
     /// Represents a value in relation to a value on the image
     /// </summary>
-    internal struct ValueSize : IEquatable<ValueSize>
+    internal readonly struct ValueSize : IEquatable<ValueSize>
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="ValueSize"/> struct.

src/ImageSharp/Processing/Processors/Dithering/PixelPair.cs

@@ -10,7 +10,7 @@ namespace SixLabors.ImageSharp.Processing.Processors
     /// Represents a composite pair of pixels. Used for caching color distance lookups.
     /// </summary>
     /// <typeparam name="TPixel">The pixel format.</typeparam>
-    internal struct PixelPair<TPixel> : IEquatable<PixelPair<TPixel>>
+    internal readonly struct PixelPair<TPixel> : IEquatable<PixelPair<TPixel>>
         where TPixel : struct, IPixel<TPixel>
     {
         /// <summary>