Changeset 1541

Timestamp:

05/23/10 01:07:22 (15 years ago)

Author:

rsinfu

Message:

Fixed covariance check (function safety).

Files:

• trunk/phobos/std/traits.d (modified) (2 diffs)

trunk/phobos/std/traits.d

@@ -1529 +1529 @@
-    template checkSTC()
-    {
-        // Note the order of arguments.  The convertion order Lwr -> Upr is
-        // correct since Upr should be semantically 'narrower' than Lwr.
-        enum ok = isStorageClassImplicitlyConvertible!(Lwr, Upr);
-    }
-    /*
-     * Check for function attributes:
-     *  - require exact match for ref and @property
-     *  - overrider can add pure and nothrow, but can't remove them
-trust: ?
+@safe and @trusted are covariant with each other, unremovable
-     */
-    template checkAttributes()
-    {
-        alias FunctionAttribute FA;
-        enum uprAtts = functionAttributes!(Upr);
-        enum lwrAtts = functionAttributes!(Lwr);
-        //
-        enum WANT_EXACT = FA.REF | FA.PROPERTY;
-TRUST
+SAFETY
-        enum ok =
-(uprAtts & WANT_EXACT) ==
-(uprAtts & FA.PURE   ) >=
-(uprAtts & FA.NOTHROW) >=
-(uprAtts & TRUST     ) >= (lwrAtts & TRUST     )) ;  // XXX
+  (uprAtts & WANT_EXACT) ==  
+  (uprAtts & FA.PURE   ) >=  
+  (uprAtts & FA.NOTHROW) >=  
+!!(uprAtts & SAFETY    ) >= !!(lwrAtts & SAFETY    )) ;
-    }
-    /*
-     * Check for return type: usual implicit convertion.
-     */
-    template checkReturnType()
-    {
-        enum ok = is(ReturnType!(Upr) : ReturnType!(Lwr));
-    }
-    /*
-     * Check for parameters:
@@ -1636 +1636 @@
-    static assert(! isCovariantWith!(BaseB.test, DerivB_1.test));
-    static assert(! isCovariantWith!(BaseB.test, DerivB_2.test));
-    static assert(! isCovariantWith!(BaseB.test, DerivB_3.test));
-
-    // function storage class
-    interface BaseC            {          void test()      ; }
-    interface DerivC_1 : BaseC { override void test() const; }
-    static assert(isCovariantWith!(DerivC_1.test, BaseC.test));
-    static assert(! isCovariantWith!(BaseC.test, DerivC_1.test));
-
-trust
+increasing safety
-    interface BaseE            {          void test()         ; }
-    interface DerivE_1 : BaseE { override void test() @safe   ; }
-    interface DerivE_2 : BaseE { override void test() @trusted; }
-    static assert(isCovariantWith!(DerivE_1.test, BaseE.test));
-    static assert(isCovariantWith!(DerivE_2.test, BaseE.test));
-    static assert(! isCovariantWith!(BaseE.test, DerivE_1.test));
-    static assert(! isCovariantWith!(BaseE.test, DerivE_2.test));
+
+    // @safe and @trusted
+    interface BaseF
+    {
+        void test1() @safe;
+        void test2() @trusted;
+    }
+    interface DerivF : BaseF
+    {
+        override void test1() @trusted;
+        override void test2() @safe;
+    }
+    static assert(isCovariantWith!(DerivF.test1, BaseF.test1));
+    static assert(isCovariantWith!(DerivF.test2, BaseF.test2));
-}
-
-
-//::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::://
-// isSomething
-//::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::://
-
-/**
- * Detect whether T is a built-in integral type. Types $(D bool), $(D
- * char), $(D wchar), and $(D dchar) are not considered integral.