feat: resolve #38

Author: Vyacheslav

Src/StackMemoryCollections/GenerateCommonHelpers.cs

@@ -0,0 +1,43 @@
+using Microsoft.CodeAnalysis;
+using System.Collections.Generic;
+using System.Text;
+
+namespace StackMemoryCollections
+{
+    public partial class Generator
+    {
+        private void GenerateCommonHelpers(
+            in List<INamedTypeSymbol> typeHelpers,
+            in GeneratorExecutionContext context,
+            in StringBuilder builder
+            )
+        {
+            if (typeHelpers.Count == 0)
+            {
+                return;
+            }
+            builder.Clear();
+            builder.Append($@"
+/*
+{Resource.License}
+*/
+
+using System;
+using System.Runtime.CompilerServices;
+
+namespace StackMemoryCollections
+{{
+    public unsafe static class CommonHelper
+    {{
+        public static bool IsNull(in void* ptr)
+        {{
+            return *((byte*)ptr) == 0;
+        }}
+    }}
+}}
+");
+
+            context.AddSource($"CommonHelper.g.cs", builder.ToString());
+        }
+    }
+}

Src/StackMemoryCollections/GenerateHelpers.cs

@@ -1,7 +1,6 @@
 using Microsoft.CodeAnalysis;
 using System;
 using System.Collections.Generic;
-using System.IO;
 using System.Linq;
 using System.Text;
 
@@ -28,7 +27,9 @@ in StringBuilder builder
 
                 GenerateStart(in builder, in currentType);
                 GenerateSize(in builder, in typeInfo);
-                
+                GenerateIsNullable(in builder, in typeInfo);
+
+
                 for (int j = 0; j < typeInfo.Members.Count; j++)
                 {
                     MemberInfo memberInfo = typeInfo.Members[j];
@@ -93,6 +94,20 @@ public static nuint GetSize()
             return {typeInfo.Members.Sum(s => s.Size) + (typeInfo.IsValueType ? 0 : 1)};
         }}
 
+");
+        }
+
+        private void GenerateIsNullable(
+            in StringBuilder builder,
+            in TypeInfo typeInfo
+            )
+        {
+            builder.Append($@"
+        public static bool IsNullable()
+        {{
+            return {(!typeInfo.IsValueType).ToString().ToLowerInvariant()};
+        }}
+
 ");
         }
 

Src/StackMemoryCollections/Generator.cs

@@ -43,6 +43,7 @@ out var containCollections
                 GenerateMemory(in context, in builder);
             }
 
+            GenerateCommonHelpers(in typeHelpers, in context, in builder);
             GenerateHelpers(in typeHelpers, in context, in infos, in builder);
             GenerateWrappers(in typeWrappers, in context, in infos, in builder);
             GenerateStack(in typeGeneratedStack, in context, in infos, in builder);