[Version 9.0] Feature support for native sized integers (nint, and nuint)

standard/arrays.md

@@ -112,7 +112,7 @@ Elements of arrays created by *array_creation_expression*s are always initialize
 
 ## 17.4 Array element access
 
-Array elements are accessed using the *array access* variant of *element_access* expressions ([§12.8.12.2](expressions.md#128122-array-access)) of the form `A[I₁, I₂, ..., Iₓ]`, where `A` is an expression of an array type and each `Iₑ` is an expression of type `int`, `uint`, `long`, `ulong`, or can be implicitly converted to one or more of these types. The result of an array access is a variable reference ([§9.5](variables.md#95-variable-references)) to the array element selected by the indices.
+Array elements are accessed using the *array access* variant of *element_access* expressions ([§12.8.12.2](expressions.md#128122-array-access)) of the form `A[I₁, I₂, ..., Iₓ]`, where `A` is an expression of an array type and each `Iₑ` is an expression of type `int`, `uint`, `nint`, `nuint`, `long`, `ulong`, or can be implicitly converted to one or more of these types. The result of an array access is a variable reference ([§9.5](variables.md#95-variable-references)) to the array element selected by the indices.
 
 Array elements of single-dimensional arrays can also be accessed using an array access expression where the sole index, `I₁`, is an expression of type `Index`, `Range`, or can be implicitly converted to one or both of these types. If `I₁` is of type `Index`, or has been implicitly converted to that type, then the result of the array access is a variable reference to the array element selected by the index value. If `I₁` is of type `Range`, or has been implicitly converted to that type, then the result of the element access is a new array formed from a shallow copy of the array elements with indices in the `Range`, maintaining the element order.
 

standard/classes.md

@@ -397,7 +397,7 @@
     : 'where' type_parameter ':' type_parameter_constraints
     ;
 
 type_parameter_constraints
     : primary_constraint (',' secondary_constraints)? (',' constructor_constraint)?
     | secondary_constraints (',' constructor_constraint)?
     | constructor_constraint
@@ -506,15 +506,15 @@
 >     static void M()
 >     {
 >         // nonnull constraint allows nonnullable struct type argument
 >         A<int> x1;
 >         // possible warning: nonnull constraint prohibits nullable struct type argument
 >         A<int?> x2;
 >         // nonnull constraint allows nonnullable class type argument
 >         A<C> x3;
 >         // possible warning: nonnull constraint prohibits nullable class type argument
 >         A<C?> x4;
 >         // nonnullable base class requirement allows nonnullable class type argument
 >         B1<C> x5;
 >         // possible warning: nonnullable base class requirement prohibits nullable
 >         // class type argument
 >         B1<C?> x6;
@@ -1556,7 +1556,7 @@
 
 The *type* of a *constant_declaration* specifies the type of the members introduced by the declaration. The type is followed by a list of *constant_declarator*s ([§13.6.3](statements.md#1363-local-constant-declarations)), each of which introduces a new member. A *constant_declarator* consists of an *identifier* that names the member, followed by an “`=`” token, followed by a *constant_expression* ([§12.25](expressions.md#1225-constant-expressions)) that gives the value of the member.
 
-The *type* specified in a constant declaration shall be `sbyte`, `byte`, `short`, `ushort`, `int`, `uint`, `long`, `ulong`, `char`, `float`, `double`, `decimal`, `bool`, `string`, an *enum_type*, or a *reference_type*. Each *constant_expression* shall yield a value of the target type or of a type that can be converted to the target type by an implicit conversion ([§10.2](conversions.md#102-implicit-conversions)).
+The *type* specified in a constant declaration shall be `sbyte`, `byte`, `short`, `ushort`, `int`, `uint`, `nint`, `nuint`, `long`, `ulong`, `char`, `float`, `double`, `decimal`, `bool`, `string`, an *enum_type*, or a *reference_type*. Each *constant_expression* shall yield a value of the target type or of a type that can be converted to the target type by an implicit conversion ([§10.2](conversions.md#102-implicit-conversions)).
 
 The *type* of a constant shall be at least as accessible as the constant itself ([§7.5.5](basic-concepts.md#755-accessibility-constraints)).
 
@@ -1790,7 +1790,7 @@
 
 - A *reference_type*.
 - A *type_parameter* that is known to be a reference type ([§15.2.5](classes.md#1525-type-parameter-constraints)).
-- The type `byte`, `sbyte`, `short`, `ushort`, `int`, `uint`, `char`, `float`, `bool`, `System.IntPtr`, or `System.UIntPtr`.
+- The type `byte`, `sbyte`, `short`, `ushort`, `int`, `uint`, `nint`, `nuint`, `char`, `float`, `bool`, `System.IntPtr`, or `System.UIntPtr`.
 - An *enum_type* having an *enum_base* type of `byte`, `sbyte`, `short`, `ushort`, `int`, or `uint`.
 
 > *Example*: The example
@@ -3465,7 +3465,7 @@
 >     static void Main()
 >     {
 >         field = 10;
 >         Console.WriteLine(Property); // Prints 10
 >         Property = 20;               // This invokes the get accessor, then assigns
 >                                      // via the resulting variable reference
 >         Console.WriteLine(field);    // Prints 20
@@ -4580,7 +4580,7 @@
     : '!'
     ;
 
 overloadable_unary_operator
     : '+' | '-' | logical_negation_operator | '~' | '++' | '--' | 'true' | 'false'
     ;
 

standard/conversions.md

@@ -83,6 +83,7 @@
 - Between `object` and `dynamic`.
 - Between all tuple types with the same arity, and the corresponding constructed `ValueTuple<...>` type, when an identity conversion exists between each pair of corresponding element types.
 - Between types constructed from the same generic type where there exists an identity conversion between each corresponding type argument.
+- Between array types containing elements of type `T` and `S`, such as `T[]` and `S[]`, where the rank of the two arrays is the same and there is an identity conversion between `T` and `S`.
 
 > *Example*: The following illustrates the recursive nature of the third rule:
 >
@@ -115,22 +116,26 @@
 
 In most cases, an identity conversion has no effect at runtime. However, since floating point operations may be performed at higher precision than prescribed by their type ([§8.3.7](types.md#837-floating-point-types)), assignment of their results may result in a loss of precision, and explicit casts are guaranteed to reduce precision to what is prescribed by the type ([§12.9.8](expressions.md#1298-cast-expressions)).
 
+There is an identity conversion between `nint` and `System.IntPtr`, and between `nuint` and `System.UIntPtr`.
+
 ### 10.2.3 Implicit numeric conversions
 
 The implicit numeric conversions are:
 
-- From `sbyte` to `short`, `int`, `long`, `float`, `double`, or `decimal`.
-- From `byte` to `short`, `ushort`, `int`, `uint`, `long`, `ulong`, `float`, `double`, or `decimal`.
-- From `short` to `int`, `long`, `float`, `double`, or `decimal`.
-- From `ushort` to `int`, `uint`, `long`, `ulong`, `float`, `double`, or `decimal`.
-- From `int` to `long`, `float`, `double`, or `decimal`.
-- From `uint` to `long`, `ulong`, `float`, `double`, or `decimal`.
+- From `sbyte` to `short`, `int`, `nint`, `long`, `float`, `double`, or `decimal`.
+- From `byte` to `short`, `ushort`, `int`, `uint`, `nint`, `nuint`, `long`, `ulong`, `float`, `double`, or `decimal`.
+- From `short` to `int`, `nint`, `long`, `float`, `double`, or `decimal`.
+- From `ushort` to `int`, `uint`, `nint`, `nuint`, `long`, `ulong`, `float`, `double`, or `decimal`.
+- From `int` to `nint`, `long`, `float`, `double`, or `decimal`.
+- From `uint` to `nuint`, `long`, `ulong`, `float`, `double`, or `decimal`.
+- From `nint` to `long`, `float`, `double`, or `decimal`.
+- From `nuint` to `ulong`, `float`, `double`, or `decimal`.
 - From `long` to `float`, `double`, or `decimal`.
 - From `ulong` to `float`, `double`, or `decimal`.
-- From `char` to `ushort`, `int`, `uint`, `long`, `ulong`, `float`, `double`, or `decimal`.
+- From `char` to `ushort`, `int`, `uint`, `nint`, `nuint`, `long`, `ulong`, `float`, `double`, or `decimal`.
 - From `float` to `double`.
 
-Conversions from `int`, `uint`, `long` or `ulong` to `float` and from `long` or `ulong` to `double` may cause a loss of precision, but will never cause a loss of magnitude. The other implicit numeric conversions never lose any information.
+Conversions from `int`, `uint`, `nint`, `nuint`, `long` or `ulong` to `float` and from `nint`, `nuint`, `long` or `ulong` to `double` may cause a loss of precision, but will never cause a loss of magnitude. The other implicit numeric conversions never lose any information.
 
 There are no predefined implicit conversions to the `char` type, so values of the other integral types do not automatically convert to the `char` type.
 
@@ -315,9 +320,13 @@
 
 An implicit constant expression conversion permits the following conversions:
 
-- A *constant_expression* ([§12.25](expressions.md#1225-constant-expressions)) of type `int` can be converted to type `sbyte`, `byte`, `short`, `ushort`, `uint`, or `ulong`, provided the value of the *constant_expression* is within the range of the destination type.
+- A *constant_expression* ([§12.25](expressions.md#1225-constant-expressions)) of type `int` can be converted to type `sbyte`, `byte`, `short`, `ushort`, `uint`, `nuint`, or `ulong`, provided the value of the *constant_expression* is within the range of the destination type.
 - A *constant_expression* of type `long` can be converted to type `ulong`, provided the value of the *constant_expression* is not negative.
 
+The range for constants of type `nint` is the same range as `int`, and the range for constants of type `nuint` is the same range as `uint` ([§12.25](expressions.md#1225-constant-expressions)).
+
+> *Note*: This is a consequence of `nint`/`nuint` being the same size as, or larger than, `int`/`uint` ([§8.3.6](types.md#836-integral-types)). *end note*
+
 ### 10.2.12 Implicit conversions involving type parameters
 
 For a *type_parameter* `T` that is known to be a reference type ([§15.2.5](classes.md#1525-type-parameter-constraints)), the following implicit reference conversions ([§10.2.8](conversions.md#1028-implicit-reference-conversions)) exist:
@@ -413,18 +422,20 @@
 
 The explicit numeric conversions are the conversions from a *numeric_type* to another *numeric_type* for which an implicit numeric conversion ([§10.2.3](conversions.md#1023-implicit-numeric-conversions)) does not already exist:
 
-- From `sbyte` to `byte`, `ushort`, `uint`, `ulong`, or `char`.
+- From `sbyte` to `byte`, `ushort`, `uint`, `ulong`, `nuint`, or `char`.
 - From `byte` to `sbyte` or `char`.
-- From `short` to `sbyte`, `byte`, `ushort`, `uint`, `ulong`, or `char`.
+- From `short` to `sbyte`, `byte`, `ushort`, `uint`, `nuint`, `ulong`, or `char`.
 - From `ushort` to `sbyte`, `byte`, `short`, or `char`.
-- From `int` to `sbyte`, `byte`, `short`, `ushort`, `uint`, `ulong`, or `char`.
-- From `uint` to `sbyte`, `byte`, `short`, `ushort`, `int`, or `char`.
-- From `long` to `sbyte`, `byte`, `short`, `ushort`, `int`, `uint`, `ulong`, or `char`.
-- From `ulong` to `sbyte`, `byte`, `short`, `ushort`, `int`, `uint`, `long`, or `char`.
+- From `int` to `sbyte`, `byte`, `short`, `ushort`, `uint`, `nuint`, `ulong`, or `char`.
+- From `uint` to `sbyte`, `byte`, `short`, `ushort`, `int`, `nint`, or `char`.
+- From `nint` to `sbyte`, `byte`, `short`, `ushort`, `int`, `uint`, `nuint`, `ulong`, or `char`.
+- From `nuint` to `sbyte`, `byte`, `short`, `ushort`, `int`, `uint`, `nint`, `long`, or `char`.
+- From `long` to `sbyte`, `byte`, `short`, `ushort`, `int`, `uint`, `nint`, `nuint`, `ulong`, or `char`.
+- From `ulong` to `sbyte`, `byte`, `short`, `ushort`, `int`, `uint`, `nint`, `nuint`, `long`, or `char`.
 - From `char` to `sbyte`, `byte`, or `short`.
-- From `float` to `sbyte`, `byte`, `short`, `ushort`, `int`, `uint`, `long`, `ulong`, `char`, or `decimal`.
-- From `double` to `sbyte`, `byte`, `short`, `ushort`, `int`, `uint`, `long`, `ulong`, `char`, `float`, or `decimal`.
-- From `decimal` to `sbyte`, `byte`, `short`, `ushort`, `int`, `uint`, `long`, `ulong`, `char`, `float`, or `double`.
+- From `float` to `sbyte`, `byte`, `short`, `ushort`, `int`, `uint`, `nint`, `nuint`, `long`, `ulong`, `char`, or `decimal`.
+- From `double` to `sbyte`, `byte`, `short`, `ushort`, `int`, `uint`, `nint`, `nuint`, `long`, `ulong`, `char`, `float`, or `decimal`.
+- From `decimal` to `sbyte`, `byte`, `short`, `ushort`, `int`, `uint`, `nint`, `nuint`, `long`, `ulong`, `char`, `float`, or `double`.
 
 Because the explicit conversions include all implicit and explicit numeric conversions, it is always possible to convert from any *numeric_type* to any other *numeric_type* using a cast expression ([§12.9.8](expressions.md#1298-cast-expressions)).
 
@@ -458,8 +469,8 @@
 
 The explicit enumeration conversions are:
 
-- From `sbyte`, `byte`, `short`, `ushort`, `int`, `uint`, `long`, `ulong`, `char`, `float`, `double`, or `decimal` to any *enum_type*.
-- From any *enum_type* to `sbyte`, `byte`, `short`, `ushort`, `int`, `uint`, `long`, `ulong`, `char`, `float`, `double`, or `decimal`.
+- From `sbyte`, `byte`, `short`, `ushort`, `int`, `uint`, `nint`, `nuint`, `long`, `ulong`, `char`, `float`, `double`, or `decimal` to any *enum_type*.
+- From any *enum_type* to `sbyte`, `byte`, `short`, `ushort`, `int`, `uint`, `nint`, `nuint`, `long`, `ulong`, `char`, `float`, `double`, or `decimal`.
 - From any *enum_type* to any other *enum_type*.
 
 An explicit enumeration conversion between two types is processed by treating any participating *enum_type* as the underlying type of that *enum_type*, and then performing an implicit or explicit numeric conversion between the resulting types.
@@ -791,7 +802,7 @@
 >
 > var amt6 = 66036;           // var types amt6 as int
 > var dose6 = (Dose)amt6;     // amt3 is int, int to ushort conversion added
 >                             // warning as information loss may occur
 > Console.WriteLine(dose6);   // outputs 500mg, not 66036mg, due to information loss
 >
 > // Using a constructor instead of user-defined conversion:

standard/enums.md

@@ -44,9 +44,7 @@ enum_body
     ;
 ```
 
-Each enum type has a corresponding integral type called the ***underlying type*** of the enum type. This underlying type shall be able to represent all the enumerator values defined in the enumeration. If the *enum_base* is present, it explicitly declares the underlying type. The underlying type shall be one of the *integral types* ([§8.3.6](types.md#836-integral-types)) other than `char`. The underlying type may be specified either by an `integral_type` ([§8.3.5](types.md#835-simple-types)), or an `integral_type_name`. The `integral_type_name` is resolved in the same way as `type_name` ([§7.8.1](basic-concepts.md#781-general)), including taking any using directives ([§14.5](namespaces.md#145-using-directives)) into account.
-
-> *Note*: The `char` type cannot be used as an underlying type, either by keyword or via an `integral_type_name`. *end note*
+Each enum type has a corresponding integral type called the ***underlying type*** of the enum type. This underlying type shall be able to represent all the enumerator values defined in the enumeration. If the *enum_base* is present, it explicitly declares the underlying type. The underlying type shall be one of the *integral types* ([§8.3.6](types.md#836-integral-types)) other than `nint`, `nuint`, and `char`. The underlying type may be specified either by an `integral_type` ([§8.3.5](types.md#835-simple-types)), or an `integral_type_name`. The `integral_type_name` is resolved in the same way as `type_name` ([§7.8.1](basic-concepts.md#781-general)), including taking any using directives ([§14.5](namespaces.md#145-using-directives)) into account.
 
 An enum declaration that does not explicitly declare an underlying type has an underlying type of `int`.