-- C840001.A -- -- Grant of Unlimited Rights -- -- Under contracts F33600-87-D-0337, F33600-84-D-0280, MDA903-79-C-0687, -- F08630-91-C-0015, and DCA100-97-D-0025, the U.S. Government obtained -- unlimited rights in the software and documentation contained herein. -- Unlimited rights are defined in DFAR 252.227-7013(a)(19). By making -- this public release, the Government intends to confer upon all -- recipients unlimited rights equal to those held by the Government. -- These rights include rights to use, duplicate, release or disclose the -- released technical data and computer software in whole or in part, in -- any manner and for any purpose whatsoever, and to have or permit others -- to do so. -- -- DISCLAIMER -- -- ALL MATERIALS OR INFORMATION HEREIN RELEASED, MADE AVAILABLE OR -- DISCLOSED ARE AS IS. THE GOVERNMENT MAKES NO EXPRESS OR IMPLIED -- WARRANTY AS TO ANY MATTER WHATSOEVER, INCLUDING THE CONDITIONS OF THE -- SOFTWARE, DOCUMENTATION OR OTHER INFORMATION RELEASED, MADE AVAILABLE -- OR DISCLOSED, OR THE OWNERSHIP, MERCHANTABILITY, OR FITNESS FOR A -- PARTICULAR PURPOSE OF SAID MATERIAL. --* -- -- OBJECTIVE: -- Check that, for the type determined by the subtype mark of a use type -- clause, the declaration of each primitive operator is use-visible -- within the scope of the clause, even if explicit operators with the -- same names as the type's operators are declared for the subtype. Check -- that a call to such an operator executes the body of the type's -- operation. -- -- TEST DESCRIPTION: -- A type may declare a primitive operator, and a subtype of that type -- may overload the operator. If a use type clause names the subtype, -- it is the primitive operator of the type (not the subtype) which -- is made directly visible, and the primitive operator may be called -- unambiguously. Such a call executes the body of the type's operation. -- -- In a package, declare a type for which a predefined operator is -- overridden. In another package, declare a subtype of the type in the -- previous package. Declare another version of the predefined operator -- for the subtype. -- -- The main program declares objects of both the type and the explicit -- subtype, and uses the "**" operator for both. In all cases, the -- operator declared for the 1st subtype should be the one executed, -- since it is the primitive operators of the *type* that are made -- visible; the operators which were declared for the explicit subtype -- are not primitive operators of the type, since they were declared in -- a separate package from the original type. -- -- -- CHANGE HISTORY: -- 06 Dec 94 SAIC ACVC 2.0 -- 23 Sep 99 RLB Added test case where operator made visible is -- not visible by selection (as in AI-00122). -- --! package C840001_0 is -- Usage scenario: the predefined operators for a floating point type -- are overridden in order to take advantage of improved algorithms. type Precision_Float is new Float range -100.0 .. 100.0; -- Implicit: function "**" (Left: Precision_Float; Right: Integer'Base) -- return Precision_Float; function "**" (Left: Precision_Float; Right: Integer'Base) return Precision_Float; -- Overrides predefined operator. function "+" (Right: Precision_Float) return Precision_Float; -- Overrides predefined operator. -- ... Other overridden operations. TC_Expected : constant Precision_Float := 68.0; end C840001_0; --==================================================================-- package body C840001_0 is function "**" (Left: Precision_Float; Right: Integer'Base) return Precision_Float is begin -- ... Utilize desired algorithm. return (TC_Expected); -- Artificial for testing purposes. end "**"; function "+" (Right: Precision_Float) return Precision_Float is -- Overrides predefined operator. begin return Right*2.0; end "+"; end C840001_0; --==================================================================-- -- Take advantage of some even better algorithms designed for positive -- floating point values. with C840001_0; package C840001_1 is subtype Precision_Pos_Float is C840001_0.Precision_Float range 0.0 .. 100.0; -- This is not a new type, so it has no primitives of it own. However, it -- can declare another version of the operator and call it as long as both it -- and the corresponding operator of the 1st subtype are not directly visible -- in the same place. function "**" (Left: Precision_Pos_Float; Right: Natural'Base) return Precision_Pos_Float; -- Accepts only positive exponent. end C840001_1; --==================================================================-- package body C840001_1 is function "**" (Left: Precision_Pos_Float; Right: Natural'Base) return Precision_Pos_Float is begin -- ... Utilize some other algorithms. return 57.0; -- Artificial for testing purposes. end "**"; end C840001_1; --==================================================================-- with Report; with C840001_1; procedure C840001_2 is -- Note that C840001_0 and it's contents is not visible in any form here. TC_Operand : C840001_1.Precision_Pos_Float := 41.0; TC_Operand2 : C840001_1.Precision_Pos_Float; use type C840001_1.Precision_Pos_Float; -- Makes the operators of its parent type directly visible, even though -- the parent type and operators are not otherwise visible at all. begin TC_Operand2 := +TC_Operand; -- Overridden operator is visible and called. if TC_Operand2 /= 82.0 then -- Predefined equality. Report.Failed ("3rd test: type's overridden operation not called for " & "operand of 1st subtype"); end if; if TC_Operand + 3.0 >= TC_Operand2 - 13.0 then -- Various predefined operators. Report.Failed ("3rd test: wrong result from predefined operators"); end if; end C840001_2; --==================================================================-- with C840001_0; with C840001_1; with C840001_2; with Report; procedure C840001 is begin Report.Test ("C840001", "Check that, for the type determined by the " & "subtype mark of a use type clause, the declaration of " & "each primitive operator is use-visible within the scope " & "of the clause, even if explicit operators with the same " & "names as the type's operators are declared for the subtype"); Use_Type_Precision_Pos_Float: declare TC_Operand : C840001_0.Precision_Float := C840001_0.Precision_Float(-2.0); TC_Positive_Operand : C840001_1.Precision_Pos_Float := 6.0; TC_Actual_Type : C840001_0.Precision_Float; TC_Actual_Subtype : C840001_1.Precision_Pos_Float; use type C840001_1.Precision_Pos_Float; -- Both calls to "**" should return 68.0 (that is, Precision_Float's -- operation should be called). begin TC_Actual_Type := TC_Operand**2; if C840001_0."/="(TC_Actual_Type, C840001_0.TC_Expected) then Report.Failed ("1st block: type's operation not called for " & "operand of 1st subtype"); end if; TC_Actual_Subtype := TC_Positive_Operand**2; if not (C840001_0."=" (TC_Actual_Subtype, C840001_0.TC_Expected)) then Report.Failed ("1st block: type's operation not called for " & "operand of explicit subtype"); end if; end Use_Type_Precision_Pos_Float; Use_Type_Precision_Float: declare TC_Operand : C840001_0.Precision_Float := C840001_0.Precision_Float(4.0); TC_Positive_Operand : C840001_1.Precision_Pos_Float := 7.0; TC_Actual_Type : C840001_0.Precision_Float; TC_Actual_Subtype : C840001_1.Precision_Pos_Float; use type C840001_0.Precision_Float; -- Again, both calls to "**" should return 68.0. begin TC_Actual_Type := TC_Operand**2; if C840001_0."/="(TC_Actual_Type, C840001_0.TC_Expected) then Report.Failed ("2nd block: type's operation not called for " & "operand of 1st subtype"); end if; TC_Actual_Subtype := TC_Positive_Operand**2; if not C840001_0."=" (TC_Actual_Subtype, C840001_0.TC_Expected) then Report.Failed ("2nd block: type's operation not called for " & "operand of explicit subtype"); end if; end Use_Type_Precision_Float; C840001_2; -- 3rd test. Report.Result; end C840001;