Avoid OverflowException in Boolean.TryFormat

`MemoryMarshal.AsBytes` would throw unnecessarily when `destination.Length` exceeds 0x3FFFFFFF.
dotnet · Oct 5, 2024 · 1a4c249 · 1a4c249
1 parent 3bcaadb
commit 1a4c249
Showing 1 changed file with 4 additions and 4 deletions.
diff --git a/src/libraries/System.Private.CoreLib/src/System/Boolean.cs b/src/libraries/System.Private.CoreLib/src/System/Boolean.cs
@@ -96,20 +96,20 @@ public bool TryFormat(Span<char> destination, out int charsWritten)
         {
             if (m_value)
             {
-                if (destination.Length > 3)
+                if (destination.Length >= 4)
                 {
                     ulong true_val = BitConverter.IsLittleEndian ? 0x65007500720054ul : 0x54007200750065ul; // "True"
-                    MemoryMarshal.Write(MemoryMarshal.AsBytes(destination), in true_val);
+                    Unsafe.WriteUnaligned(ref Unsafe.As<char, byte>(ref MemoryMarshal.GetReference(destination)), true_val);
                     charsWritten = 4;
                     return true;
                 }
             }
             else
             {
-                if (destination.Length > 4)
+                if (destination.Length >= 5)
                 {
                     ulong fals_val = BitConverter.IsLittleEndian ? 0x73006C00610046ul : 0x460061006C0073ul; // "Fals"
-                    MemoryMarshal.Write(MemoryMarshal.AsBytes(destination), in fals_val);
+                    Unsafe.WriteUnaligned(ref Unsafe.As<char, byte>(ref MemoryMarshal.GetReference(destination)), fals_val);
                     destination[4] = 'e';
                     charsWritten = 5;
                     return true;