Installed allocator into std::function

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@111672 91177308-0d34-0410-b5e6-96231b3b80d8

test/utilities/function.objects/func.wrap/func.wrap.func/func.wrap.func.mod/assign_F_alloc.pass.cpp

@@ -16,7 +16,45 @@
 #include <functional>
 #include <cassert>
 
+#include "../test_allocator.h"
+
+class A
+{
+    int data_[10];
+public:
+    static int count;
+
+    A()
+    {
+        ++count;
+        for (int i = 0; i < 10; ++i)
+            data_[i] = i;
+    }
+
+    A(const A&) {++count;}
+
+    ~A() {--count;}
+
+    int operator()(int i) const
+    {
+        for (int j = 0; j < 10; ++j)
+            i += data_[j];
+        return i;
+    }
+
+    int foo(int) const {return 1;}
+};
+
+int A::count = 0;
+
 int main()
 {
-#error template<class F, class A> void assign(F&&, const A&); not implemented
+    {
+    std::function<int(int)> f;
+    f.assign(A(), test_allocator<A>());
+    assert(A::count == 1);
+    assert(f.target<A>());
+    assert(f.target<int(*)(int)>() == 0);
+    }
+    assert(A::count == 0);
 }