Added compile-fail/array1.cxx

Author: seanbaxter

libsafecxx/test/CMakeLists.txt

@@ -106,6 +106,7 @@ endfunction()
 
 add_test(NAME "safecxx-verify-headers" COMMAND "${CMAKE_COMMAND}" --build ${CMAKE_BINARY_DIR} --target "safe_cxx_verify_interface_header_sets" --config $<CONFIG)
 
+safe_cxx_compile_fail_test(array1 "use of bi depends on expired loan")
 safe_cxx_compile_fail_test(string_view1 "use of sv depends on expired loan")
 safe_cxx_compile_fail_test(box_incomplete "class incomplete is incomplete")
 safe_cxx_compile_fail_test(box1 "cannot convert prvalue int to std2::box<int>")

libsafecxx/test/compile-fail/array1.cxx

@@ -0,0 +1,19 @@
+// A test for https://github.com/cppalliance/safe-cpp/issues/72
+#feature on safety
+#include <std2.h>
+using namespace std2;
+
+int main() safe {
+  int i = 0;
+  int j = 1;
+  vector<const int^> v { ^const i, ^const j }; 
+
+  const int^ bi = v[0];
+
+  // Mutation of i while the loan in v is live should make this
+  // ill-formed.
+  i = 1;
+
+  // Keep the loan in scope.
+  int x = *bi;
+}