- (1)
- This annex summarizes the definitions given elsewhere of the
language-defined attributes.
- (2)
- P'Access
For a prefix P that denotes a subprogram:
- (3)
P'Access yields an access value that designates the subprogram denoted by
P. The type of P'Access is an access-to-subprogram type (S), as determined
by the expected type. See 3.10.2.
- (4)
- X'Access
For a prefix X that denotes an aliased view of an object:
- (5)
X'Access yields an access value that designates the object denoted by X.
The type of X'Access is an access-to-object type, as determined by the expected
type. The expected type shall be a general access type. See
3.10.2.
- (6)
- X'Address
For a prefix X that denotes an object, program unit, or
label:
- (7)
Denotes the address of the first of the storage elements allocated to X.
For a program unit or label, this value refers to the machine code associated
with the corresponding body or statement. The value of this attribute is
of type System.Address. See 13.3.
- (8)
- S'Adjacent
For every subtype S of a floating point type T:
- (9)
S'Adjacent denotes a function with the following
specification:
(10)
function S'Adjacent (X, Towards : T)
return T
- (11)
If Towards=X, the function yields X; otherwise, it yields the machine number
of the type T adjacent to X in the direction of Towards, if that machine
number exists. If the result would be outside the base range of S, Constraint_Error
is raised. When T'Signed_Zeros is True, a zero result has the sign of X.
When Towards is zero, its sign has no bearing on the result. See
A.5.3.
- (12)
- S'Aft
For every fixed point subtype S:
- (13)
S'Aft yields the number of decimal digits needed after the decimal point
to accommodate the delta of the subtype S, unless the delta of the subtype
S is greater than 0.1, in which case the attribute yields the value one.
(S'Aft is the smallest positive integer N for which (10**N)*S'Delta is greater
than or equal to one.) The value of this attribute is of the type universal_integer.
See 3.5.10.
- (14)
- X'Alignment
For a prefix X that denotes a subtype or object:
- (15)
The Address of an object that is allocated under control
of the implementation is an integral multiple of the
Alignment of the object (that is, the Address modulo the
Alignment is zero). The offset of a record component is a
multiple of the Alignment of the component. For an object
that is not allocated under control of the implementation
(that is, one that is imported, that is allocated by a
user-defined allocator, whose Address has been specified, or
is designated by an access value returned by an instance of
Unchecked_Conversion), the implementation may assume that the
Address is an integral multiple of its Alignment. The
implementation shall not assume a stricter alignment.
- (16)
The value of this attribute is of type universal_integer, and nonnegative;
zero means that the object is not necessarily aligned on a storage element
boundary. See 13.3.
- (17)
- S'Base
For every scalar subtype S:
- (18)
S'Base denotes an unconstrained subtype of the type of S. This unconstrained
subtype is called the base subtype of the type. See 3.5.
- (19)
- S'Bit_Order
For every specific record subtype S:
- (20)
Denotes the bit ordering for the type of S. The value of this attribute
is of type System.Bit_Order. See 13.5.3.
- (21)
- P'Body_Version
For a prefix P that statically denotes a program unit:
- (22)
Yields a value of the predefined type String that identifies the version
of the compilation unit that contains the body (but not any subunits) of
the program unit. See E.3.
- (23)
- T'Callable
For a prefix T that is of a task type (after any implicit
dereference):
- (24)
Yields the value True when the task denoted by T is callable, and False
otherwise; See 9.9.
- (25)
- E'Caller
For a prefix E that denotes an entry_declaration:
- (26)
Yields a value of the type Task_ID that identifies the task whose call is
now being serviced. Use of this attribute is allowed only inside an entry_body
or accept_statement corresponding to the entry_declaration denoted by E.
See C.7.1.
- (27)
- S'Ceiling
For every subtype S of a floating point type T:
- (28)
S'Ceiling denotes a function with the following
specification:
(29)
function S'Ceiling (X : T)
return T
- (30)
The function yields the value Ceiling(X), i.e., the smallest (most negative)
integral value greater than or equal to X. When X is zero, the result has
the sign of X; a zero result otherwise has a negative sign when S'Signed_Zeros
is True. See A.5.3.
- (31)
- S'Class
For every subtype S of a tagged type T (specific or
class-wide):
- (32)
S'Class denotes a subtype of the class-wide type (called
T'Class in this International Standard) for the class rooted
at T (or if S already denotes a class-wide subtype, then
S'Class is the same as S).
- (33)
S'Class is unconstrained. However, if S is constrained, then the values
of S'Class are only those that when converted to the type T belong to S.
See 3.9.
- (34)
- S'Class
For every subtype S of an untagged private type whose full
view is tagged:
- (35)
Denotes the class-wide subtype corresponding to the full view of S. This
attribute is allowed only from the beginning of the private part in which
the full view is declared, until the declaration of the full view. After
the full view, the Class attribute of the full view can be used. See
7.3.1.
- (36)
- X'Component_Size
For a prefix X that denotes an array subtype or array object
(after any implicit dereference):
- (37)
Denotes the size in bits of components of the type of X. The value of this
attribute is of type universal_integer. See 13.3.
- (38)
- S'Compose
For every subtype S of a floating point type T:
- (39)
S'Compose denotes a function with the following
specification:
(40)
function S'Compose (Fraction : T;
Exponent : universal_integer)
return T
- (41)
Let v be the value Fraction*T'Machine_Radix**(Exponent-k), where k is the
normalized exponent of Fraction. If v is a machine number of the type T,
or if |v|>=T'Model_Small, the function yields v; otherwise, it yields
either one of the machine numbers of the type T adjacent to v. Constraint_Error
is optionally raised if v is outside the base range of S. A zero result
has the sign of Fraction when S'Signed_Zeros is True. See
A.5.3.
- (42)
- A'Constrained
For a prefix A that is of a discriminated type (after any
implicit dereference):
- (43)
Yields the value True if A denotes a constant, a value, or a constrained
variable, and False otherwise. See 3.7.2.
- (44)
- S'Copy_Sign
For every subtype S of a floating point type T:
- (45)
S'Copy_Sign denotes a function with the following
specification:
(46)
function S'Copy_Sign (Value, Sign : T)
return T
- (47)
If the value of Value is nonzero, the function yields a result whose magnitude
is that of Value and whose sign is that of Sign; otherwise, it yields the
value zero. Constraint_Error is optionally raised if the result is outside
the base range of S. A zero result has the sign of Sign when S'Signed_Zeros
is True. See A.5.3.
- (48)
- E'Count
For a prefix E that denotes an entry of a task or protected
unit:
- (49)
Yields the number of calls presently queued on the entry E of the current
instance of the unit. The value of this attribute is of the type universal_integer.
See 9.9.
- (50)
- S'Definite
For a prefix S that denotes a formal indefinite subtype:
- (51)
S'Definite yields True if the actual subtype corresponding to S is definite;
otherwise it yields False. The value of this attribute is of the predefined
type Boolean. See 12.5.1.
- (52)
- S'Delta
For every fixed point subtype S:
- (53)
S'Delta denotes the delta of the fixed point subtype S. The value of this
attribute is of the type universal_real. See 3.5.10.
- (54)
- S'Denorm
For every subtype S of a floating point type T:
- (55)
Yields the value True if every value expressible in the
form
+/-mantissa*T'Machine_Radix**T'Machine_Emin
where mantissa is a nonzero T'Machine_Mantissa-digit fraction in the number
base T'Machine_Radix, the first digit of which is zero, is a machine number
(see 3.5.7) of the type T; yields the value False
otherwise. The value of this attribute is of the predefined type Boolean.
See A.5.3.
- (56)
- S'Digits
For every decimal fixed point subtype S:
- (57)
S'Digits denotes the digits of the decimal fixed point subtype S, which
corresponds to the number of decimal digits that are representable in objects
of the subtype. The value of this attribute is of the type universal_integer.
See 3.5.10.
- (58)
- S'Digits
For every floating point subtype S:
- (59)
S'Digits denotes the requested decimal precision for the subtype S. The
value of this attribute is of the type universal_integer. See
3.5.8.
- (60)
- S'Exponent
For every subtype S of a floating point type T:
- (61)
S'Exponent denotes a function with the following
specification:
(62)
function S'Exponent (X : T)
return universal_integer
- (63)
The function yields the normalized exponent of X. See
A.5.3.
- (64)
- S'External_Tag
For every subtype S of a tagged type T (specific or
class-wide):
- (65)
S'External_Tag denotes an external string representation for S'Tag; it is
of the predefined type String. External_Tag may be specified for a specific
tagged type via an attribute_definition_clause; the expression of such a
clause shall be static. The default external tag representation is implementation
defined. See 3.9.2 and 13.13.2.
See 13.3.
- (66)
- A'First(N)
For a prefix A that is of an array type (after any implicit
dereference), or denotes a constrained array subtype:
- (67)
A'First(N) denotes the lower bound of the N-th index range; its type is
the corresponding index type. See 3.6.2.
- (68)
- A'First
For a prefix A that is of an array type (after any implicit
dereference), or denotes a constrained array subtype:
- (69)
A'First denotes the lower bound of the first index range; its type is the
corresponding index type. See 3.6.2.
- (70)
- S'First
For every scalar subtype S:
- (71)
S'First denotes the lower bound of the range of S. The value of this attribute
is of the type of S. See 3.5.
- (72)
- R.C'First_Bit
For a component C of a composite, non-array object R:
- (73)
Denotes the offset, from the start of the first of the storage elements
occupied by C, of the first bit occupied by C. This offset is measured in
bits. The first bit of a storage element is numbered zero. The value of
this attribute is of the type universal_integer. See
13.5.2.
- (74)
- S'Floor
For every subtype S of a floating point type T:
- (75)
S'Floor denotes a function with the following
specification:
(76)
function S'Floor (X : T)
return T
- (77)
The function yields the value Floor(X), i.e., the largest (most positive)
integral value less than or equal to X. When X is zero, the result has the
sign of X; a zero result otherwise has a positive sign. See
A.5.3.
- (78)
- S'Fore
For every fixed point subtype S:
- (79)
S'Fore yields the minimum number of characters needed before the decimal
point for the decimal representation of any value of the subtype S, assuming
that the representation does not include an exponent, but includes a one-character
prefix that is either a minus sign or a space. (This minimum number does
not include superfluous zeros or underlines, and is at least 2.) The value
of this attribute is of the type universal_integer. See
3.5.10.
- (80)
- S'Fraction
For every subtype S of a floating point type T:
- (81)
S'Fraction denotes a function with the following
specification:
(82)
function S'Fraction (X : T)
return T
- (83)
The function yields the value X*T'Machine_Radix**(-k), where k is the normalized
exponent of X. A zero result, which can only occur when X is zero, has the
sign of X. See A.5.3.
- (84)
- E'Identity
For a prefix E that denotes an exception:
- (85)
E'Identity returns the unique identity of the exception. The type of this
attribute is Exception_Id. See 11.4.1.
- (86)
- T'Identity
For a prefix T that is of a task type (after any implicit
dereference):
- (87)
Yields a value of the type Task_ID that identifies the task denoted by T.
See C.7.1.
- (88)
- S'Image
For every scalar subtype S:
- (89)
S'Image denotes a function with the following
specification:
(90)
function S'Image(Arg : S'Base)
return String
- (91)
The function returns an image of the value of Arg as a String. See 3.5.
- (92)
- S'Class'Input
For every subtype S'Class of a class-wide type T'Class:
- (93)
S'Class'Input denotes a function with the following
specification:
(94)
function S'Class'Input(
Stream : access Ada.Streams.Root_Stream_Type'Class)
return T'Class
- (95)
First reads the external tag from Stream and determines the corresponding
internal tag (by calling Tags.Internal_Tag(String'Input(Stream)) -- see
3.9) and then dispatches to the subprogram denoted by the Input attribute
of the specific type identified by the internal tag; returns that result.
See 13.13.2.
- (96)
- S'Input
For every subtype S of a specific type T:
- (97)
S'Input denotes a function with the following
specification:
(98)
function S'Input(
Stream : access Ada.Streams.Root_Stream_Type'Class)
return T
- (99)
S'Input reads and returns one value from Stream, using any bounds or discriminants
written by a corresponding S'Output to determine how much to read. See
13.13.2.
- (100)
- A'Last(N)
For a prefix A that is of an array type (after any implicit
dereference), or denotes a constrained array subtype:
- (101)
A'Last(N) denotes the upper bound of the N-th index range; its type is the
corresponding index type. See 3.6.2.
- (102)
- A'Last
For a prefix A that is of an array type (after any implicit
dereference), or denotes a constrained array subtype:
- (103)
A'Last denotes the upper bound of the first index range; its type is the
corresponding index type. See 3.6.2.
- (104)
- S'Last
For every scalar subtype S:
- (105)
S'Last denotes the upper bound of the range of S. The value of this attribute
is of the type of S. See 3.5.
- (106)
- R.C'Last_Bit
For a component C of a composite, non-array object R:
- (107)
Denotes the offset, from the start of the first of the storage elements
occupied by C, of the last bit occupied by C. This offset is measured in
bits. The value of this attribute is of the type universal_integer. See
13.5.2.
- (108)
- S'Leading_Part
For every subtype S of a floating point type T:
- (109)
S'Leading_Part denotes a function with the following
specification:
(110)
function S'Leading_Part (X : T;
Radix_Digits : universal_integer)
return T
- (111)
Let v be the value T'Machine_Radix**(k-Radix_Digits), where
k is the normalized exponent of X. The function yields the
value
- (112)
- Floor(X/v)*v, when X is nonnegative and Radix_Digits is positive;
- (113)
- Ceiling(X/v)*v, when X is negative and Radix_Digits is positive.
- (114)
Constraint_Error is raised when Radix_Digits is zero or negative. A zero
result, which can only occur when X is zero, has the sign of X. See
A.5.3.
- (115)
- A'Length(N)
For a prefix A that is of an array type (after any implicit
dereference), or denotes a constrained array subtype:
- (116)
A'Length(N) denotes the number of values of the N-th index range (zero for
a null range); its type is universal_integer. See
3.6.2.
- (117)
- A'Length
For a prefix A that is of an array type (after any implicit
dereference), or denotes a constrained array subtype:
- (118)
A'Length denotes the number of values of the first index range (zero for
a null range); its type is universal_integer. See
3.6.2.
- (119)
- S'Machine
For every subtype S of a floating point type T:
- (120)
S'Machine denotes a function with the following
specification:
(121)
function S'Machine (X : T)
return T
- (122)
If X is a machine number of the type T, the function yields X; otherwise,
it yields the value obtained by rounding or truncating X to either one of
the adjacent machine numbers of the type T. Constraint_Error is raised if
rounding or truncating X to the precision of the machine numbers results
in a value outside the base range of S. A zero result has the sign of X
when S'Signed_Zeros is True. See A.5.3.
- (123)
- S'Machine_Emax
For every subtype S of a floating point type T:
- (124)
Yields the largest (most positive) value of exponent such that every value
expressible in the canonical form (for the type T), having a mantissa of
T'Machine_Mantissa digits, is a machine number (see
3.5.7) of the type T. This attribute yields a value of the type universal_integer.
See A.5.3.
- (125)
- S'Machine_Emin
For every subtype S of a floating point type T:
- (126)
Yields the smallest (most negative) value of exponent such that every value
expressible in the canonical form (for the type T), having a mantissa of
T'Machine_Mantissa digits, is a machine number (see
3.5.7) of the type T. This attribute yields a value of the type universal_integer.
See A.5.3.
- (127)
- S'Machine_Mantissa
For every subtype S of a floating point type T:
- (128)
Yields the largest value of p such that every value expressible in the canonical
form (for the type T), having a p-digit mantissa and an exponent between
T'Machine_Emin and T'Machine_Emax, is a machine number (see
3.5.7) of the type T. This attribute yields a value of the type universal_integer.
See A.5.3.
- (129)
- S'Machine_Overflows
For every subtype S of a fixed point type T:
- (130)
Yields the value True if overflow and divide-by-zero are detected and reported
by raising Constraint_Error for every predefined operation that yields a
result of the type T; yields the value False otherwise. The value of this
attribute is of the predefined type Boolean. See A.5.4.
- (131)
- S'Machine_Overflows
For every subtype S of a floating point type T:
- (132)
Yields the value True if overflow and divide-by-zero are detected and reported
by raising Constraint_Error for every predefined operation that yields a
result of the type T; yields the value False otherwise. The value of this
attribute is of the predefined type Boolean. See A.5.3.
- (133)
- S'Machine_Radix
For every subtype S of a fixed point type T:
- (134)
Yields the radix of the hardware representation of the type T. The value
of this attribute is of the type universal_integer. See
A.5.4.
- (135)
- S'Machine_Radix
For every subtype S of a floating point type T:
- (136)
Yields the radix of the hardware representation of the type T. The value
of this attribute is of the type universal_integer. See
A.5.3.
- (137)
- S'Machine_Rounds
For every subtype S of a fixed point type T:
- (138)
Yields the value True if rounding is performed on inexact results of every
predefined operation that yields a result of the type T; yields the value
False otherwise. The value of this attribute is of the predefined type Boolean.
See A.5.4.
- (139)
- S'Machine_Rounds
For every subtype S of a floating point type T:
- (140)
Yields the value True if rounding is performed on inexact results of every
predefined operation that yields a result of the type T; yields the value
False otherwise. The value of this attribute is of the predefined type Boolean.
See A.5.3.
- (141)
- S'Max
For every scalar subtype S:
- (142)
S'Max denotes a function with the following
specification:
(143)
function S'Max(Left, Right : S'Base)
return S'Base
- (144)
The function returns the greater of the values of the two parameters. See
3.5.
- (145)
- S'Max_Size_In_Storage_Elements
- (146)
Denotes the maximum value for Size_In_Storage_Elements that will be requested
via Allocate for an access type whose designated subtype is S. The value
of this attribute is of type universal_integer. See
13.11.1.
- (147)
- S'Min
For every scalar subtype S:
- (148)
S'Min denotes a function with the following
specification:
(149)
function S'Min(Left, Right : S'Base)
return S'Base
- (150)
The function returns the lesser of the values of the two parameters. See
3.5.
- (151)
- S'Model
For every subtype S of a floating point type T:
- (152)
S'Model denotes a function with the following
specification:
(153)
function S'Model (X : T)
return T
- (154)
If the Numerics Annex is not supported, the meaning of this attribute is
implementation defined; see G.2.2 for the definition
that applies to implementations supporting the Numerics Annex. See
A.5.3.
- (155)
- S'Model_Emin
For every subtype S of a floating point type T:
- (156)
If the Numerics Annex is not supported, this attribute yields an implementation
defined value that is greater than or equal to the value of T'Machine_Emin.
See G.2.2 for further requirements that apply
to implementations supporting the Numerics Annex. The value of this attribute
is of the type universal_integer. See A.5.3.
- (157)
- S'Model_Epsilon
For every subtype S of a floating point type T:
- (158)
Yields the value T'Machine_Radix**(1-T'Model_Mantissa). The value of this
attribute is of the type universal_real. See A.5.3.
- (159)
- S'Model_Mantissa
For every subtype S of a floating point type T:
- (160)
If the Numerics Annex is not supported, this attribute yields an implementation
defined value that is greater than or equal to Ceiling(d*log (10)/log (T'Machine_Radix))+1,
where d is the requested decimal precision of T, and less than or equal
to the value of T'Machine_Mantissa. See G.2.2
for further requirements that apply to implementations supporting the Numerics
Annex. The value of this attribute is of the type universal_integer. See
A.5.3.
- (161)
- S'Model_Small
For every subtype S of a floating point type T:
- (162)
Yields the value T'Machine_Radix**(T'Model_Emin-1). The value of this attribute
is of the type universal_real. See A.5.3.
- (163)
- S'Modulus
For every modular subtype S:
- (164)
S'Modulus yields the modulus of the type of S, as a value of the type universal_integer.
See 3.5.4.
- (165)
- S'Class'Output
For every subtype S'Class of a class-wide type T'Class:
- (166)
S'Class'Output denotes a procedure with the following
specification:
(167)
procedure S'Class'Output(
Stream : access Ada.Streams.Root_Stream_Type'Class;
Item : in T'Class)
- (168)
First writes the external tag of Item to Stream (by calling String'Output(Tags.External_Tag(Item'Tag)
-- see 3.9) and then dispatches to the subprogram
denoted by the Output attribute of the specific type identified by the tag.
See 13.13.2.
- (169)
- S'Output
For every subtype S of a specific type T:
- (170)
S'Output denotes a procedure with the following
specification:
(171)
procedure S'Output(
Stream : access Ada.Streams.Root_Stream_Type'Class;
Item : in T)
- (172)
S'Output writes the value of Item to Stream, including any bounds or discriminants.
See 13.13.2.
- (173)
- D'Partition_ID
For a prefix D that denotes a library-level declaration,
excepting a declaration of or within a declared-pure library
unit:
- (174)
Denotes a value of the type universal_integer that identifies the partition
in which D was elaborated. If D denotes the declaration of a remote call
interface library unit (see E.2.3) the given partition
is the one where the body of D was elaborated. See E.1.
- (175)
- S'Pos
For every discrete subtype S:
- (176)
S'Pos denotes a function with the following
specification:
(177)
function S'Pos(Arg : S'Base)
return universal_integer
- (178)
This function returns the position number of the value of Arg, as a value
of type universal_integer. See 3.5.5.
- (179)
- R.C'Position
For a component C of a composite, non-array object R:
- (180)
Denotes the same value as R.C'Address - R'Address. The value of this attribute
is of the type universal_integer. See 13.5.2.
- (181)
- S'Pred
For every scalar subtype S:
- (182)
S'Pred denotes a function with the following
specification:
(183)
function S'Pred(Arg : S'Base)
return S'Base
- (184)
For an enumeration type, the function returns the value whose position number
is one less than that of the value of Arg; Constraint_Error is raised if
there is no such value of the type. For an integer type, the function returns
the result of subtracting one from the value of Arg. For a fixed point type,
the function returns the result of subtracting small from the value of Arg.
For a floating point type, the function returns the machine number (as defined
in 3.5.7) immediately below the value of Arg;
Constraint_Error is raised if there is no such machine number. See 3.5.
- (185)
- A'Range(N)
For a prefix A that is of an array type (after any implicit
dereference), or denotes a constrained array subtype:
- (186)
A'Range(N) is equivalent to the range A'First(N) .. A'Last(N), except that
the prefix A is only evaluated once. See 3.6.2.
- (187)
- A'Range
For a prefix A that is of an array type (after any implicit
dereference), or denotes a constrained array subtype:
- (188)
A'Range is equivalent to the range A'First .. A'Last, except that the prefix
A is only evaluated once. See 3.6.2.
- (189)
- S'Range
For every scalar subtype S:
- (190)
S'Range is equivalent to the range S'First .. S'Last. See 3.5.
- (191)
- S'Class'Read
For every subtype S'Class of a class-wide type T'Class:
- (192)
S'Class'Read denotes a procedure with the following
specification:
(193)
procedure S'Class'Read(
Stream : access Ada.Streams.Root_Stream_Type'Class;
Item : out T'Class)
- (194)
Dispatches to the subprogram denoted by the Read attribute of the specific
type identified by the tag of Item. See 13.13.2.
- (195)
- S'Read
For every subtype S of a specific type T:
- (196)
S'Read denotes a procedure with the following
specification:
(197)
procedure S'Read(
Stream : access Ada.Streams.Root_Stream_Type'Class;
Item : out T)
- (198)
S'Read reads the value of Item from Stream. See 13.13.2.
- (199)
- S'Remainder
For every subtype S of a floating point type T:
- (200)
S'Remainder denotes a function with the following
specification:
(201)
function S'Remainder (X, Y : T)
return T
- (202)
For nonzero Y, let v be the value X-n*Y, where n is the integer nearest
to the exact value of X/Y; if |n-X/Y|=1/2, then n is chosen to be even.
If v is a machine number of the type T, the function yields v; otherwise,
it yields zero. Constraint_Error is raised if Y is zero. A zero result has
the sign of X when S'Signed_Zeros is True. See A.5.3.
- (203)
- S'Round
For every decimal fixed point subtype S:
- (204)
S'Round denotes a function with the following
specification:
(205)
function S'Round(X : universal_real)
return S'Base
- (206)
The function returns the value obtained by rounding X (away from 0, if X
is midway between two values of the type of S). See
3.5.10.
- (207)
- S'Rounding
For every subtype S of a floating point type T:
- (208)
S'Rounding denotes a function with the following
specification:
(209)
function S'Rounding (X : T)
return T
- (210)
The function yields the integral value nearest to X, rounding away from
zero if X lies exactly halfway between two integers. A zero result has the
sign of X when S'Signed_Zeros is True. See A.5.3.
- (211)
- S'Safe_First
For every subtype S of a floating point type T:
- (212)
Yields the lower bound of the safe range (see 3.5.7)
of the type T. If the Numerics Annex is not supported, the value of this
attribute is implementation defined; see G.2.2
for the definition that applies to implementations supporting the Numerics
Annex. The value of this attribute is of the type universal_real. See
A.5.3.
- (213)
- S'Safe_Last
For every subtype S of a floating point type T:
- (214)
Yields the upper bound of the safe range (see 3.5.7)
of the type T. If the Numerics Annex is not supported, the value of this
attribute is implementation defined; see G.2.2
for the definition that applies to implementations supporting the Numerics
Annex. The value of this attribute is of the type universal_real. See
A.5.3.
- (215)
- S'Scale
For every decimal fixed point subtype S:
- (216)
S'Scale denotes the scale of the subtype S, defined as the value N such
that S'Delta = 10.0**(-N). The scale indicates the position of the point
relative to the rightmost significant digits of values of subtype S. The
value of this attribute is of the type universal_integer. See
3.5.10.
- (217)
- S'Scaling
For every subtype S of a floating point type T:
- (218)
S'Scaling denotes a function with the following
specification:
(219)
function S'Scaling (X : T;
Adjustment : universal_integer)
return T
- (220)
Let v be the value X*T'Machine_Radix**Adjustment. If v is a machine number
of the type T, or if |v|>=T'Model_Small, the function yields v; otherwise,
it yields either one of the machine numbers of the type T adjacent to v.
Constraint_Error is optionally raised if v is outside the base range of
S. A zero result has the sign of X when S'Signed_Zeros is True. See
A.5.3.
- (221)
- S'Signed_Zeros
For every subtype S of a floating point type T:
- (222)
Yields the value True if the hardware representation for the type T has
the capability of representing both positively and negatively signed zeros,
these being generated and used by the predefined operations of the type
T as specified in IEC 559:1989; yields the value False otherwise. The value
of this attribute is of the predefined type Boolean. See
A.5.3.
- (223)
- S'Size
- (224)
If S is definite, denotes the size (in bits) that the
implementation would choose for the following objects of
subtype S:
- (225)
- A record component of subtype S when the record
type is packed.
- (226)
- The formal parameter of an instance of Unchecked_Conversion that converts from subtype S to some
other subtype.
- (227)
If S is indefinite, the meaning is implementation defined. The value of
this attribute is of the type universal_integer. See 13.3.
- (228)
- X'Size
For a prefix X that denotes an object:
- (229)
Denotes the size in bits of the representation of the object. The value
of this attribute is of the type universal_integer. See 13.3.
- (230)
- S'Small
For every fixed point subtype S:
- (231)
S'Small denotes the small of the type of S. The value of this attribute
is of the type universal_real. See 3.5.10.
- (232)
- S'Storage_Pool
For every access subtype S:
- (233)
Denotes the storage pool of the type of S. The type of this attribute is
Root_Storage_Pool'Class. See 13.11.
- (234)
- S'Storage_Size
For every access subtype S:
- (235)
Yields the result of calling Storage_Size(S'Storage_Pool), which is intended
to be a measure of the number of storage elements reserved for the pool.
The type of this attribute is universal_integer. See 13.11.
- (236)
- T'Storage_Size
For a prefix T that denotes a task object (after any implicit
dereference):
- (237)
Denotes the number of storage elements reserved for the task. The value
of this attribute is of the type universal_integer. The Storage_Size includes
the size of the task's stack, if any. The language does not specify whether
or not it includes other storage associated with the task (such as the ``task
control block'' used by some implementations.) See 13.3.
- (238)
- S'Succ
For every scalar subtype S:
- (239)
S'Succ denotes a function with the following
specification:
(240)
function S'Succ(Arg : S'Base)
return S'Base
- (241)
For an enumeration type, the function returns the value whose position number
is one more than that of the value of Arg; Constraint_Error is raised if
there is no such value of the type. For an integer type, the function returns
the result of adding one to the value of Arg. For a fixed point type, the
function returns the result of adding small to the value of Arg. For a floating
point type, the function returns the machine number (as defined in
3.5.7) immediately above the value of Arg; Constraint_Error is raised
if there is no such machine number. See 3.5.
- (242)
- S'Tag
For every subtype S of a tagged type T (specific or
class-wide):
- (243)
S'Tag denotes the tag of the type T (or if T is class-wide, the tag of the
root type of the corresponding class). The value of this attribute is of
type Tag. See 3.9.
- (244)
- X'Tag
For a prefix X that is of a class-wide tagged type (after any
implicit dereference):
- (245)
X'Tag denotes the tag of X. The value of this attribute is of type Tag.
See 3.9.
- (246)
- T'Terminated
For a prefix T that is of a task type (after any implicit
dereference):
- (247)
Yields the value True if the task denoted by T is terminated, and False
otherwise. The value of this attribute is of the predefined type Boolean.
See 9.9.
- (248)
- S'Truncation
For every subtype S of a floating point type T:
- (249)
S'Truncation denotes a function with the following
specification:
(250)
function S'Truncation (X : T)
return T
- (251)
The function yields the value Ceiling(X) when X is negative, and Floor(X)
otherwise. A zero result has the sign of X when S'Signed_Zeros is True.
See A.5.3.
- (252)
- S'Unbiased_Rounding
For every subtype S of a floating point type T:
- (253)
S'Unbiased_Rounding denotes a function with the
following specification:
(254)
function S'Unbiased_Rounding (X : T)
return T
- (255)
The function yields the integral value nearest to X, rounding toward the
even integer if X lies exactly halfway between two integers. A zero result
has the sign of X when S'Signed_Zeros is True. See
A.5.3.
- (256)
- X'Unchecked_Access
For a prefix X that denotes an aliased view of an object:
- (257)
All rules and semantics that apply to X'Access (see
3.10.2) apply also to X'Unchecked_Access, except that, for the purposes
of accessibility rules and checks, it is as if X were declared immediately
within a library package. See 13.10.
- (258)
- S'Val
For every discrete subtype S:
- (259)
S'Val denotes a function with the following
specification:
(260)
function S'Val(Arg : universal_integer)
return S'Base
- (261)
This function returns a value of the type of S whose position number equals
the value of Arg. See 3.5.5.
- (262)
- X'Valid
For a prefix X that denotes a scalar object (after any
implicit dereference):
- (263)
Yields True if and only if the object denoted by X is normal and has a valid
representation. The value of this attribute is of the predefined type Boolean.
See 13.9.2.
- (264)
- S'Value
For every scalar subtype S:
- (265)
S'Value denotes a function with the following
specification:
(266)
function S'Value(Arg : String)
return S'Base
- (267)
This function returns a value given an image of the value as a String, ignoring
any leading or trailing spaces. See 3.5.
- (268)
- P'Version
For a prefix P that statically denotes a program unit:
- (269)
Yields a value of the predefined type String that identifies the version
of the compilation unit that contains the declaration of the program unit.
See E.3.
- (270)
- S'Wide_Image
For every scalar subtype S:
- (271)
S'Wide_Image denotes a function with the following
specification:
(272)
function S'Wide_Image(Arg : S'Base)
return Wide_String
- (273)
The function returns an image of the value of Arg, that is, a sequence of
characters representing the value in display form. See 3.5.
- (274)
- S'Wide_Value
For every scalar subtype S:
- (275)
S'Wide_Value denotes a function with the following
specification:
(276)
function S'Wide_Value(Arg : Wide_String)
return S'Base
- (277)
This function returns a value given an image of the value as a Wide_String,
ignoring any leading or trailing spaces. See 3.5.
- (278)
- S'Wide_Width
For every scalar subtype S:
- (279)
S'Wide_Width denotes the maximum length of a Wide_String returned by S'Wide_Image
over all values of the subtype S. It denotes zero for a subtype that has
a null range. Its type is universal_integer. See 3.5.
- (280)
- S'Width
For every scalar subtype S:
- (281)
S'Width denotes the maximum length of a String returned by S'Image over
all values of the subtype S. It denotes zero for a subtype that has a null
range. Its type is universal_integer. See 3.5.
- (282)
- S'Class'Write
For every subtype S'Class of a class-wide type T'Class:
- (283)
S'Class'Write denotes a procedure with the following
specification:
(284)
procedure S'Class'Write(
Stream : access Ada.Streams.Root_Stream_Type'Class;
Item : in T'Class)
- (285)
Dispatches to the subprogram denoted by the Write attribute of the specific
type identified by the tag of Item. See 13.13.2.
- (286)
- S'Write
For every subtype S of a specific type T:
- (287)
S'Write denotes a procedure with the following
specification:
(288)
procedure S'Write(
Stream : access Ada.Streams.Root_Stream_Type'Class;
Item : in T)
- (289)
S'Write writes the value of Item to Stream. See 13.13.2.
-- Email comments, additions, corrections, gripes, kudos, etc. to:
Magnus Kempe -- Magnus.Kempe@di.epfl.ch
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