[c++-concepts] constrained friends

[Andrew Sutton]

Added tests for constrained friends.  No code, we already to the right thing.

2014-08-15  Andrew Sutton  <andrew.n.sut...@gmail.com>

Add tests for constrained friends.
    * gcc/testsuite/g++.dg/concepts/friend1.C: New.
    * gcc/testsuite/g++.dg/concepts/friend2.C: New.

Andrew

Index: gcc/testsuite/g++.dg/concepts/friend2.C
===================================================================
--- gcc/testsuite/g++.dg/concepts/friend2.C	(revision 0)
+++ gcc/testsuite/g++.dg/concepts/friend2.C	(revision 0)
@@ -0,0 +1,20 @@
+// { dg-options "-std=c++1z" }
+
+template<typename T>
+  concept bool Eq() { return requires(T t) { t == t; }; }
+
+template<Eq T> struct Foo { };
+
+template<typename T>
+  struct S { // { dg-error "constraint failure" }
+    template<Eq U> friend class Bar;
+
+    friend class Foo<T>;
+  };
+
+struct X { };
+
+int main() {
+  S<int> si; // OK
+  S<X> sx;
+}
Index: gcc/testsuite/g++.dg/concepts/friend1.C
===================================================================
--- gcc/testsuite/g++.dg/concepts/friend1.C	(revision 0)
+++ gcc/testsuite/g++.dg/concepts/friend1.C	(revision 0)
@@ -0,0 +1,33 @@
+// { dg-options "-std=c++1z" }
+
+template<typename T>
+  concept bool Eq() { return requires(T t) { t == t; }; }
+
+struct Nt {
+  template<Eq T> friend void f(T) { }
+} nt;
+
+template<typename T> struct S;
+
+template<Eq T>
+  void proc(S<T>*);
+
+template<typename T>
+  struct S {
+    friend bool operator==(S, S) requires Eq<T>() { return true; }
+
+    friend void proc<>(S*); // { dg-error "does not match any template declaration" }
+  };
+
+struct X { } x;
+
+int main() {
+  f(0); // OK
+  f(x); // { dg-error "cannot call" }
+
+  S<int> si;
+  si == si; // OK
+
+  S<X> sx; 
+  sx == sx; // { dg-error "no match" }
+}