Prepare ntcore for merge into allwpilib.

ntcore/src/test/native/cpp/ValueMatcher.cpp

@@ -0,0 +1,33 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2017-2018. All Rights Reserved.                        */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "ValueMatcher.h"
+
+#include "TestPrinters.h"
+
+namespace nt {
+
+bool ValueMatcher::MatchAndExplain(
+    std::shared_ptr<Value> val,
+    ::testing::MatchResultListener* listener) const {
+  if ((!val && goodval) || (val && !goodval) ||
+      (val && goodval && *val != *goodval)) {
+    return false;
+  }
+  return true;
+}
+
+void ValueMatcher::DescribeTo(::std::ostream* os) const {
+  PrintTo(goodval, os);
+}
+
+void ValueMatcher::DescribeNegationTo(::std::ostream* os) const {
+  *os << "is not equal to ";
+  PrintTo(goodval, os);
+}
+
+}  // namespace nt