moved code with preprocessor directives to extension methods

Author: epeshk

src/Serilog.Extensions.Logging/Extensions/Logging/SerilogLogger.cs

@@ -103,20 +103,12 @@ LogEvent PrepareWrite<TState>(LogEventLevel level, EventId eventId, TState state
                 {
                     messageTemplate = value;
                 }
-#if NET6_0_OR_GREATER || NETSTANDARD2_1_OR_GREATER
-                else if (property.Key.StartsWith('@'))
-#else
-                else if (property.Key.StartsWith("@"))
-#endif
+                else if (property.Key.StartsWithAtSign())
                 {
                     if (_logger.BindProperty(GetKeyWithoutFirstSymbol(DestructureDictionary, property.Key), property.Value, true, out var destructured))
                         properties.Add(destructured);
                 }
-#if NET6_0_OR_GREATER || NETSTANDARD2_1_OR_GREATER
-                else if (property.Key.StartsWith('$'))
-#else
-                else if (property.Key.StartsWith("$"))
-#endif
+                else if (property.Key.StartsWithDollarSign())
                 {
                     if (_logger.BindProperty(GetKeyWithoutFirstSymbol(StringifyDictionary, property.Key), property.Value?.ToString(), true, out var stringified))
                         properties.Add(stringified);

src/Serilog.Extensions.Logging/Extensions/Logging/SerilogLoggerScope.cs

@@ -54,20 +54,12 @@ public static void EnrichWithStateAndCreateScopeItem(LogEvent logEvent, ILogEven
         void AddProperty(string key, object? value)
         {
             var destructureObject = false;
-#if NET6_0_OR_GREATER || NETSTANDARD2_1_OR_GREATER
-            if (key.StartsWith('@'))
-#else
-            if (key.StartsWith("@"))
-#endif
+            if (key.StartsWithAtSign())
             {
                 key = SerilogLogger.GetKeyWithoutFirstSymbol(SerilogLogger.DestructureDictionary, key);
                 destructureObject = true;
             }
-#if NET6_0_OR_GREATER || NETSTANDARD2_1_OR_GREATER
-            else if (key.StartsWith('$'))
-#else
-            else if (key.StartsWith("$"))
-#endif
+            else if (key.StartsWithDollarSign())
             {
                 key = SerilogLogger.GetKeyWithoutFirstSymbol(SerilogLogger.StringifyDictionary, key);
                 value = value?.ToString();

src/Serilog.Extensions.Logging/Extensions/StringExtensions.cs

@@ -0,0 +1,26 @@
+using System.Runtime.CompilerServices;
+
+namespace Serilog.Extensions;
+
+static class StringExtensions
+{
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static bool StartsWithDollarSign(this string value)
+    {
+#if NET6_0_OR_GREATER || NETSTANDARD2_1_OR_GREATER
+        return value.StartsWith('$');
+#else
+        return value.StartsWith("$");
+#endif
+    }
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static bool StartsWithAtSign(this string value)
+    {
+#if NET6_0_OR_GREATER || NETSTANDARD2_1_OR_GREATER
+        return value.StartsWith('@');
+#else
+        return value.StartsWith("@");
+#endif
+    }
+}