From 6ee244bc45b828b138aeaaf91e0005f4f4a50ae8 Mon Sep 17 00:00:00 2001
From: Andrej Mitrovic <andrej.mitrovich@gmail.com>
Date: Mon, 10 Dec 2012 18:34:15 +0100
Subject: [PATCH] Fixes Issue 9136 - Add isNested trait for aggregates and
 functions.

---
 src/idgen.c            |  1 +
 src/traits.c           | 28 ++++++++++++++++++++++++++++
 test/runnable/traits.d | 30 ++++++++++++++++++++++++++++++
 3 files changed, 59 insertions(+)

diff --git a/src/idgen.c b/src/idgen.c
index 7b9896a4e6e7..c0c07d12e1d1 100644
--- a/src/idgen.c
+++ b/src/idgen.c
@@ -307,6 +307,7 @@ Msgtable msgtable[] =
     { "isAssociativeArray" },
     { "isFinalClass" },
     { "isPOD" },
+    { "isNested" },
     { "isFloating" },
     { "isIntegral" },
     { "isScalar" },
diff --git a/src/traits.c b/src/traits.c
index 7115819526ea..4a8c821edfc2 100644
--- a/src/traits.c
+++ b/src/traits.c
@@ -168,6 +168,34 @@ Expression *TraitsExp::semantic(Scope *sc)
         }
         goto Ltrue;
     }
+    else if (ident == Id::isNested)
+    {
+        if (dim != 1)
+            goto Ldimerror;
+        Object *o = (*args)[0];
+        Dsymbol *s = getDsymbol(o);
+        AggregateDeclaration *a;
+        FuncDeclaration *f;
+
+        if (!s) { }
+        else if ((a = s->isAggregateDeclaration()) != NULL)
+        {
+            if (a->isnested)
+                goto Ltrue;
+            else
+                goto Lfalse;
+        }
+        else if ((f = s->isFuncDeclaration()) != NULL)
+        {
+            if (f->isNested())
+                goto Ltrue;
+            else
+                goto Lfalse;
+        }
+
+        error("aggregate or function expected instead of '%s'", o->toChars());
+        goto Lfalse;
+    }
     else if (ident == Id::isAbstractFunction)
     {
         FuncDeclaration *f;
diff --git a/test/runnable/traits.d b/test/runnable/traits.d
index ccf5f0adb69d..9712b37fcbdf 100644
--- a/test/runnable/traits.d
+++ b/test/runnable/traits.d
@@ -1043,6 +1043,35 @@ void test9552()
 
 /*************************************************************/
 
+void test9136()
+{
+    int x;
+    struct S1 { void f() { x++; } }
+    struct U1 { void f() { x++; } }
+    static struct S2 { }
+    static struct S3 { S1 s; }
+    static struct U2 { }
+    void f1() { x++; }
+    static void f2() { }
+
+    static assert(__traits(isNested, S1));
+    static assert(__traits(isNested, U1));
+    static assert(!__traits(isNested, S2));
+    static assert(!__traits(isNested, S3));
+    static assert(!__traits(isNested, U2));
+    static assert(!__traits(compiles, __traits(isNested, int) ));
+    static assert(!__traits(compiles, __traits(isNested, f1, f2) ));
+    static assert(__traits(isNested, f1));
+    static assert(!__traits(isNested, f2));
+
+    static class A { static class SC { } class NC { } }
+    static assert(!__traits(isNested, A));
+    static assert(!__traits(isNested, A.SC));
+    static assert(__traits(isNested, A.NC));
+}
+
+/********************************************************/
+
 int main()
 {
     test1();
@@ -1075,6 +1104,7 @@ int main()
     test5978();
     test7408();
     test9552();
+    test9136();
 
     writeln("Success");
     return 0;