add some return type deduction test (c++14)

.gitignore

@@ -19,3 +19,4 @@ lvalues
 bad_alloc
 rtti
 future
+return-type-deduction

CMakeLists.txt

@@ -21,3 +21,9 @@ add_executable(rtti rtti.cpp)
 
 add_executable(future future.cpp)
 set_target_properties(future PROPERTIES LINK_FLAGS "-pthread")
+
+# those are c++14:
+
+add_executable(return-type-deduction return-type-deduction.cpp)
+#XXX a bit ugly, as the -std=c++1y gets appended to the other flags, which say -std=c++11
+set_source_files_properties(return-type-deduction.cpp PROPERTIES COMPILE_FLAGS "-std=c++1y")

return-type-deduction.cpp

@@ -0,0 +1,16 @@
+/* http://en.wikipedia.org/wiki/C++14 */
+
+#include <cassert>
+#include <iostream>
+
+auto sum(int i) {
+  if (i == 1)
+    return i;               // return type deduced as int
+  else
+    return sum (i-1) + i;   // ok to call it now
+}
+
+int main() {
+  assert(sum(3) == 6);
+  assert(sum(10) == 55);
+}