Changeset 1756

Timestamp:

07/14/10 01:17:00 (14 years ago)

Author:

andrei

Message:

Added hasMember

Files:

• trunk/phobos/std/traits.d (modified) (1 diff)

trunk/phobos/std/traits.d

@@ -1208 +1208 @@
-
-unittest
-{
-    static assert(!hasElaborateAssign!int);
-    struct S { void opAssign(S) {} }
-    static assert(hasElaborateAssign!S);
-    struct S1 { void opAssign(ref S1) {} }
-    static assert(hasElaborateAssign!S1);
-    struct S2 { void opAssign(S1) {} }
-    static assert(!hasElaborateAssign!S2);
+}
+
+/**
+   Yields $(D true) if and only if $(D T) is a $(D struct) or a $(D
+   class) that defines a symbol called $(D name).
+ */
+template hasMember(T, string name)
+{
+    static if (is(T == struct) || is(T == class))
+    {
+        enum bool hasMember =
+            staticIndexOf!(name, __traits(allMembers, T)) != -1;
+    }
+    else
+    {
+        enum bool hasMember = false;
+    }
+}
+
+unittest
+{
+    //pragma(msg, __traits(allMembers, void delegate()));
+    static assert(!hasMember!(int, "blah"));
+    struct S1 { int blah; }
+    static assert(hasMember!(S1, "blah"));
+    struct S2 { int blah(); }
+    static assert(hasMember!(S2, "blah"));
+    struct C1 { int blah; }
+    static assert(hasMember!(C1, "blah"));
+    struct C2 { int blah(); }
+    static assert(hasMember!(C2, "blah"));
-}
-
-//::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::://
-// Classes and Interfaces
-//::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::://
-
-/***
- * Get a $(D_PARAM TypeTuple) of the base class and base interfaces of
- * this class or interface. $(D_PARAM BaseTypeTuple!(Object)) returns
- * the empty type tuple.