Merge from core

test/teststruct.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <string>
+
+#define YAML_ASSERT(cond)               \
+  do {                                  \
+    if (!(cond))                        \
+      return "  Assert failed: " #cond; \
+  } while (false)
+
+namespace Test {
+struct TEST {
+  TEST() : ok(false) {}
+  TEST(bool ok_) : ok(ok_) {}
+  TEST(const char *error_) : ok(false), error(error_) {}
+
+  bool ok;
+  std::string error;
+};
+}