[.NET] Move the nfloat type to the ObjCRuntime namespace for .NET. (#13092)

Also move the NMath type from the System namespace to the ObjCRuntime namespace.

Ref: #13087

Author: rolfbjarne

dotnet/BreakingChanges.md

@@ -0,0 +1,21 @@
+# Breaking changes in .NET
+
+## System.nfloat moved to ObjCRuntime.nfloat
+
+The `nfloat` type moved from the `System` namespace to the `ObjCRuntime` namespace.
+
+* Code that references the `nfloat` type might not compile unless the `ObjCRuntime` namespace is imported.
+
+  Fix: add `using ObjCRuntime` to the file in question.
+
+* Code that references the full typename, `System.nfloat` won't compile.
+
+  Fix: use `ObjCRuntime.nfloat` instead.
+
+## System.NMath moved to ObjCRuntime.NMath
+
+The `NMath` type moved from the `System` namespace to the `ObjCRuntime` namespace.
+
+* Code that uses the `NMath` type won't compile unless the `ObjCRuntime` namespace is imported.
+
+  Fix: add `using ObjCRuntime` to the file in question.

external/MonoTouch.Dialog

@@ -1513,7 +1513,11 @@
 		func = to_managed ? (void *) xamarin_nsnumber_to_nint : (void *) xamarin_nint_to_nsnumber;
 	} else if (!strcmp (fullname, "System.nuint")) {
 		func = to_managed ? (void *) xamarin_nsnumber_to_nuint : (void *) xamarin_nuint_to_nsnumber;
+#if DOTNET
+	} else if (!strcmp (fullname, "ObjCRuntime.nfloat")) {
+#else
 	} else if (!strcmp (fullname, "System.nfloat")) {
+#endif
 		func = to_managed ? (void *) xamarin_nsnumber_to_nfloat : (void *) xamarin_nfloat_to_nsnumber;
 	} else if (mono_class_is_enum (managedType)) {
 		MonoType *baseType = mono_class_enum_basetype (managedType);

external/Touch.Unit

@@ -22,6 +22,9 @@
 //
 using System;
 using System.Runtime.InteropServices;
+
+using ObjCRuntime;
+
 namespace AppKit {
 	[StructLayout (LayoutKind.Sequential)]
 	public struct NSEdgeInsets {

runtime/trampolines.m

@@ -1,8 +1,10 @@
 #if !__MACCATALYST__
 using System;
 using System.Diagnostics;
+
 using Foundation;
 using CoreGraphics;
+using ObjCRuntime;
 
 namespace AppKit {
 

src/AppKit/Defs.cs

@@ -9,6 +9,7 @@
 #if MONOMAC
 
 using System;
+using ObjCRuntime;
 
 namespace Foundation
 {

src/AppKit/NSEvent.cs

@@ -7,9 +7,14 @@
 // Copyright 2014 Xamarin Inc. All rights reserved.
 //
 
+using System;
 using System.Runtime.CompilerServices;
 
+#if NET
+namespace ObjCRuntime
+#else
 namespace System
+#endif
 {
 	public static class NMath
 	{

src/Foundation/NSNumber.mac.cs

@@ -24,6 +24,10 @@
 // Copyright 2013 Xamarin, Inc. All rights reserved.
 //
 
+#if NET
+#define OBJCRUNTIME_nfloat
+#endif
+
 <#@ template language="C#v3.5" #>
 <#@ import namespace="System" #>
 <#@ import namespace="System.Collections.Generic" #>
@@ -32,8 +36,8 @@ using System.Diagnostics;
 using System.Globalization;
 using System.Runtime.InteropServices;
 
-namespace System
-{
+using ObjCRuntime;
+
 <#
 	foreach (var type in new [] {
 		new { NSName = "nint", CilName32 = "Int32", CilName64 = "Int64", IsIntegerType = true },
@@ -56,6 +60,12 @@ namespace System
 			binops.Add ("^");
 		}
 #>
+#if OBJCRUNTIME_<#= type.NSName #>
+namespace ObjCRuntime
+#else
+namespace System
+#endif
+{
 	[Serializable]
 	[DebuggerDisplay ("{v,nq}")]
 	public unsafe struct <#= type.NSName #> : IFormattable, IConvertible, IComparable, IComparable<<#= type.NSName #>>, IEquatable <<#= type.NSName #>>
@@ -429,5 +439,5 @@ namespace System
 				Marshal.WriteIntPtr (destination, i * <#= type.NSName #>.Size, (IntPtr)source [i + startIndex]);
 		}
 	}
-<# } #>
 }
+<# } #>

src/NativeTypes/NMath.cs

@@ -88,6 +88,14 @@ abstract partial class Registrar {
 		public Application App { get; protected set; }
 #endif
 
+#if MMP || MTOUCH || BUNDLER
+		static string NFloatTypeName { get => Driver.IsDotNet ? "ObjCRuntime.nfloat" : "System.nfloat"; }
+#elif NET
+		const string NFloatTypeName = "ObjCRuntime.nfloat";
+#else
+		const string NFloatTypeName = "System.nfloat";
+#endif
+
 		Dictionary<TAssembly, object> assemblies = new Dictionary<TAssembly, object> (); // Use Dictionary instead of HashSet to avoid pulling in System.Core.dll.
 		// locking: all accesses must lock 'types'.
 		Dictionary<TType, ObjCType> types = new Dictionary<TType, ObjCType> ();
@@ -715,10 +723,11 @@ bool IsValidToManagedTypeConversion (TType inputType, TType outputType)
 					case "System.nuint":
 					case "System.Single":
 					case "System.Double":
-					case "System.nfloat":
 					case "System.Boolean":
 						return true;
 					default:
+						if (outputTypeName == NFloatTypeName)
+							return true;
 						return Registrar.IsEnum (underlyingOutputType);
 					}
 				} else if (Registrar.Is (underlyingInputType, Foundation, "NSValue")) {
@@ -2641,12 +2650,13 @@ protected string ToSignature (TType type, ObjCMember member, ref bool success, b
 				return Is64Bits ? "q" : "i";
 			case "System.nuint":
 				return Is64Bits ? "Q" : "I";
-			case "System.nfloat":
-				return Is64Bits ? "d" : "f";
 			case "System.DateTime":
 				throw CreateException (4102, member, Errors.MT4102, "System.DateTime", "Foundation.NSDate", member.FullName);
 			}
 
+			if (typeFullName == NFloatTypeName)
+				return Is64Bits ? "d" : "f";
+
 			if (Is (type, ObjCRuntime, "Selector"))
 				return ":";