Add Sign() for signed numeric types

Behaves as Math.Sign()

X10D/src/ByteExtensions/SByteExtensions.cs

@@ -1,3 +1,6 @@
+using System.Diagnostics.Contracts;
+using System.Runtime.CompilerServices;
+
 namespace X10D;
 
 /// <summary>
@@ -43,4 +46,38 @@ public static class SByteExtensions
     {
         return ((short)value).IsPrime();
     }
+
+    /// <summary>
+    ///     Returns an integer that indicates the sign of this 8-bit signed integer.
+    /// </summary>
+    /// <param name="value">A signed number.</param>
+    /// <returns>
+    ///     A number that indicates the sign of <paramref name="value" />, as shown in the following table.
+    ///
+    ///     <list type="table">
+    ///         <listheader>
+    ///             <term>Return value</term>
+    ///             <description>Meaning</description>
+    ///         </listheader>
+    ///
+    ///         <item>
+    ///             <term>-1</term>
+    ///             <description><paramref name="value" /> is less than zero.</description>
+    ///         </item>
+    ///         <item>
+    ///             <term>0</term>
+    ///             <description><paramref name="value" /> is equal to zero.</description>
+    ///         </item>
+    ///         <item>
+    ///             <term>1</term>
+    ///             <description><paramref name="value" /> is greater than zero.</description>
+    ///         </item>
+    ///     </list>
+    /// </returns>
+    [Pure]
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+    public static int Sign(this sbyte value)
+    {
+        return Math.Sign(value);
+    }
 }

X10D/src/DoubleExtensions/DoubleExtensions.cs

@@ -1,4 +1,7 @@
-namespace X10D;
+using System.Diagnostics.Contracts;
+using System.Runtime.CompilerServices;
+
+namespace X10D;
 
 /// <summary>
 ///     Extension methods for <see cref="double" />.
@@ -123,4 +126,38 @@ public static class DoubleExtensions
     {
         return Math.Round(value / nearest) * nearest;
     }
+
+    /// <summary>
+    ///     Returns an integer that indicates the sign of this double-precision floating-point number.
+    /// </summary>
+    /// <param name="value">A signed number.</param>
+    /// <returns>
+    ///     A number that indicates the sign of <paramref name="value" />, as shown in the following table.
+    ///
+    ///     <list type="table">
+    ///         <listheader>
+    ///             <term>Return value</term>
+    ///             <description>Meaning</description>
+    ///         </listheader>
+    ///
+    ///         <item>
+    ///             <term>-1</term>
+    ///             <description><paramref name="value" /> is less than zero.</description>
+    ///         </item>
+    ///         <item>
+    ///             <term>0</term>
+    ///             <description><paramref name="value" /> is equal to zero.</description>
+    ///         </item>
+    ///         <item>
+    ///             <term>1</term>
+    ///             <description><paramref name="value" /> is greater than zero.</description>
+    ///         </item>
+    ///     </list>
+    /// </returns>
+    [Pure]
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+    public static int Sign(this double value)
+    {
+        return Math.Sign(value);
+    }
 }

X10D/src/Int16Extensions/Int16Extensions.cs

@@ -1,4 +1,6 @@
+using System.Diagnostics.Contracts;
 using System.Net;
+using System.Runtime.CompilerServices;
 
 namespace X10D;
 
@@ -177,6 +179,40 @@ public static class Int16Extensions
         return MathUtils.Lerp(value, target, alpha);
     }
 
+    /// <summary>
+    ///     Returns an integer that indicates the sign of this 16-bit signed integer.
+    /// </summary>
+    /// <param name="value">A signed number.</param>
+    /// <returns>
+    ///     A number that indicates the sign of <paramref name="value" />, as shown in the following table.
+    ///
+    ///     <list type="table">
+    ///         <listheader>
+    ///             <term>Return value</term>
+    ///             <description>Meaning</description>
+    ///         </listheader>
+    ///
+    ///         <item>
+    ///             <term>-1</term>
+    ///             <description><paramref name="value" /> is less than zero.</description>
+    ///         </item>
+    ///         <item>
+    ///             <term>0</term>
+    ///             <description><paramref name="value" /> is equal to zero.</description>
+    ///         </item>
+    ///         <item>
+    ///             <term>1</term>
+    ///             <description><paramref name="value" /> is greater than zero.</description>
+    ///         </item>
+    ///     </list>
+    /// </returns>
+    [Pure]
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+    public static int Sign(this short value)
+    {
+        return Math.Sign(value);
+    }
+
     /// <summary>
     ///     Converts an integer value from network byte order to host byte order.
     /// </summary>

X10D/src/Int32Extensions/Int32Extensions.cs

@@ -1,4 +1,6 @@
-using System.Net;
+using System.Diagnostics.Contracts;
+using System.Net;
+using System.Runtime.CompilerServices;
 
 namespace X10D;
 
@@ -241,6 +243,40 @@ public static class Int32Extensions
         return r < 0 ? r + divisor : r;
     }
 
+    /// <summary>
+    ///     Returns an integer that indicates the sign of this 32-bit signed integer.
+    /// </summary>
+    /// <param name="value">A signed number.</param>
+    /// <returns>
+    ///     A number that indicates the sign of <paramref name="value" />, as shown in the following table.
+    ///
+    ///     <list type="table">
+    ///         <listheader>
+    ///             <term>Return value</term>
+    ///             <description>Meaning</description>
+    ///         </listheader>
+    ///
+    ///         <item>
+    ///             <term>-1</term>
+    ///             <description><paramref name="value" /> is less than zero.</description>
+    ///         </item>
+    ///         <item>
+    ///             <term>0</term>
+    ///             <description><paramref name="value" /> is equal to zero.</description>
+    ///         </item>
+    ///         <item>
+    ///             <term>1</term>
+    ///             <description><paramref name="value" /> is greater than zero.</description>
+    ///         </item>
+    ///     </list>
+    /// </returns>
+    [Pure]
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+    public static int Sign(this int value)
+    {
+        return Math.Sign(value);
+    }
+
     /// <summary>
     ///     Converts an integer value from network byte order to host byte order.
     /// </summary>

X10D/src/Int64Extensions/Int64Extensions.cs

@@ -1,4 +1,6 @@
-using System.Net;
+using System.Diagnostics.Contracts;
+using System.Net;
+using System.Runtime.CompilerServices;
 
 namespace X10D;
 
@@ -202,6 +204,40 @@ public static class Int64Extensions
         return MathUtils.Lerp(value, target, alpha);
     }
 
+    /// <summary>
+    ///     Returns an integer that indicates the sign of this 64-bit signed integer.
+    /// </summary>
+    /// <param name="value">A signed number.</param>
+    /// <returns>
+    ///     A number that indicates the sign of <paramref name="value" />, as shown in the following table.
+    ///
+    ///     <list type="table">
+    ///         <listheader>
+    ///             <term>Return value</term>
+    ///             <description>Meaning</description>
+    ///         </listheader>
+    ///
+    ///         <item>
+    ///             <term>-1</term>
+    ///             <description><paramref name="value" /> is less than zero.</description>
+    ///         </item>
+    ///         <item>
+    ///             <term>0</term>
+    ///             <description><paramref name="value" /> is equal to zero.</description>
+    ///         </item>
+    ///         <item>
+    ///             <term>1</term>
+    ///             <description><paramref name="value" /> is greater than zero.</description>
+    ///         </item>
+    ///     </list>
+    /// </returns>
+    [Pure]
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+    public static int Sign(this long value)
+    {
+        return Math.Sign(value);
+    }
+
     /// <summary>
     ///     Converts an integer value from network byte order to host byte order.
     /// </summary>

X10D/src/SingleExtensions/SingleExtensions.cs

@@ -1,4 +1,7 @@
-namespace X10D;
+using System.Diagnostics.Contracts;
+using System.Runtime.CompilerServices;
+
+namespace X10D;
 
 /// <summary>
 ///     Extension methods for <see cref="float" />.
@@ -123,4 +126,38 @@ public static class SingleExtensions
     {
         return MathF.Round(value / nearest) * nearest;
     }
+
+    /// <summary>
+    ///     Returns an integer that indicates the sign of this single-precision floating-point number.
+    /// </summary>
+    /// <param name="value">A signed number.</param>
+    /// <returns>
+    ///     A number that indicates the sign of <paramref name="value" />, as shown in the following table.
+    ///
+    ///     <list type="table">
+    ///         <listheader>
+    ///             <term>Return value</term>
+    ///             <description>Meaning</description>
+    ///         </listheader>
+    ///
+    ///         <item>
+    ///             <term>-1</term>
+    ///             <description><paramref name="value" /> is less than zero.</description>
+    ///         </item>
+    ///         <item>
+    ///             <term>0</term>
+    ///             <description><paramref name="value" /> is equal to zero.</description>
+    ///         </item>
+    ///         <item>
+    ///             <term>1</term>
+    ///             <description><paramref name="value" /> is greater than zero.</description>
+    ///         </item>
+    ///     </list>
+    /// </returns>
+    [Pure]
+    [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
+    public static int Sign(this float value)
+    {
+        return MathF.Sign(value);
+    }
 }