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

standard/arrays.md

@@ -36,7 +36,7 @@
 A *non_array_type* is any *type* that is not itself an *array_type*.
 
 When determining the rank and element type of array type as specified below, only the *rank_specifier*s in the outer-most production are considered, so in the production `array_type nullable_type_annotation rank_specifier+`, any `rank_specifier` within the `array_type` is ignored.
 
 The rank of an array type is given by the leftmost *rank_specifier* in the *array_type*: A *rank_specifier* indicates that the array is an array with a rank of one plus the number of “`,`” tokens in the *rank_specifier*.
 
 The element type of an array type is the type that results from deleting the leftmost *rank_specifier* from the *array_type*.
@@ -154,7 +154,7 @@
 
 ## 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 array 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

@@ -3,28 +3,28 @@
 ## 15.1 General
 
 A class is a data structure that may contain data members (constants and fields), function members (methods, properties, events, indexers, operators, instance constructors, finalizers, and static constructors), and nested types. Class types support inheritance, a mechanism whereby a ***derived class*** can extend and specialize a ***base class***.
 
 Structs ([§16](structs.md#16-structs)) and interfaces ([§19](interfaces.md#19-interfaces)) have members similar to classes but with certain restrictions. This clause defines the declarations for classes and class members. The clauses for structs and interfaces define the restrictions for those types in terms of the corresponding declarations in class types.
 
 ## 15.2 Class declarations
 
 ### 15.2.1 General
 
 A *class_declaration* is a *type_declaration* ([§14.7](namespaces.md#147-type-declarations)) that declares a new class.
 
 ```ANTLR
 class_declaration
     : attributes? class_modifier* 'partial'? 'class' identifier
         type_parameter_list? class_base? type_parameter_constraints_clause*
         class_body ';'?
     ;
 ```
 
 A *class_declaration* consists of an optional set of *attributes* ([§23](attributes.md#23-attributes)), followed by an optional set of *class_modifier*s ([§15.2.2](classes.md#1522-class-modifiers)), followed by an optional `partial` modifier ([§15.2.7](classes.md#1527-partial-type-declarations)), followed by the keyword `class` and an *identifier* that names the class, followed by an optional *type_parameter_list* ([§15.2.3](classes.md#1523-type-parameters)), followed by an optional *class_base* specification ([§15.2.4](classes.md#1524-class-base-specification)), followed by an optional set of *type_parameter_constraints_clause*s ([§15.2.5](classes.md#1525-type-parameter-constraints)), followed by a *class_body* ([§15.2.6](classes.md#1526-class-body)), optionally followed by a semicolon.
 
 A class declaration shall not supply *type_parameter_constraints_clause*s unless it also supplies a *type_parameter_list*.
 
 A class declaration that supplies a *type_parameter_list* is a generic class declaration. Additionally, any class nested inside a generic class declaration or a generic struct declaration is itself a generic class declaration, since type arguments for the containing type shall be supplied to create a constructed type ([§8.4](types.md#84-constructed-types)).
 
 ### 15.2.2 Class modifiers
 
@@ -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

standard/conversions.md

@@ -25,7 +25,7 @@
 > ```csharp
 > enum Color { Red, Blue, Green }
 >
 > // The expression 0 converts implicitly to enum types
 > Color c0 = 0;
 >
 > // Other int expressions need explicit conversion
@@ -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:
@@ -419,18 +428,20 @@
 
 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)).
 
@@ -464,8 +475,8 @@
 
 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.

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`.