From 77c8c3bf0b095b37d84c41f7dc44a24156b90ae6 Mon Sep 17 00:00:00 2001
From: Jose Luis Blanco Claraco <joseluisblancoc@gmail.com>
Date: Tue, 28 Jul 2020 00:22:09 +0200
Subject: [PATCH] Values initializer_list constructor

---
 gtsam/nonlinear/Values.cpp           |  6 ++++++
 gtsam/nonlinear/Values.h             |  7 +++++++
 gtsam/nonlinear/tests/testValues.cpp | 30 ++++++++++++++++++++++++++++
 3 files changed, 43 insertions(+)

diff --git a/gtsam/nonlinear/Values.cpp b/gtsam/nonlinear/Values.cpp
index 7e13a072a..13be88ce1 100644
--- a/gtsam/nonlinear/Values.cpp
+++ b/gtsam/nonlinear/Values.cpp
@@ -52,6 +52,12 @@ namespace gtsam {
   Values::Values(Values&& other) : values_(std::move(other.values_)) {
   }
 
+  /* ************************************************************************* */
+  Values::Values(std::initializer_list<ConstKeyValuePair> init) {
+    for (const auto &kv : init)
+      insert(kv.key, kv.value);
+  }
+
   /* ************************************************************************* */
   Values::Values(const Values& other, const VectorValues& delta) {
     for (const_iterator key_value = other.begin(); key_value != other.end(); ++key_value) {
diff --git a/gtsam/nonlinear/Values.h b/gtsam/nonlinear/Values.h
index bc64f2612..aadbcf394 100644
--- a/gtsam/nonlinear/Values.h
+++ b/gtsam/nonlinear/Values.h
@@ -149,6 +149,13 @@ namespace gtsam {
 
     /** Move constructor */
     Values(Values&& other);
+    
+    /** Constructor from initializer list. Example usage:
+     * \code
+     * Values v = {{k1, genericValue(pose1)}, {k2, genericValue(point2)}};
+     * \endcode
+     */
+    Values(std::initializer_list<ConstKeyValuePair> init);
 
     /** Construct from a Values and an update vector: identical to other.retract(delta) */
     Values(const Values& other, const VectorValues& delta);
diff --git a/gtsam/nonlinear/tests/testValues.cpp b/gtsam/nonlinear/tests/testValues.cpp
index 2f624f527..388bcf568 100644
--- a/gtsam/nonlinear/tests/testValues.cpp
+++ b/gtsam/nonlinear/tests/testValues.cpp
@@ -606,6 +606,36 @@ TEST(Values, Demangle) {
   EXPECT(assert_equal(expected, actual));
 }
 
+/* ************************************************************************* */
+TEST(Values, brace_initializer) {
+  const Pose2 poseA(1.0, 2.0, 0.3), poseC(.0, .0, .0);
+  const Pose3 poseB(Pose2(0.1, 0.2, 0.3));
+
+  {
+    Values values;
+    EXPECT_LONGS_EQUAL(0, values.size());
+    values = { {key1, genericValue(1.0)} };
+    EXPECT_LONGS_EQUAL(1, values.size());
+    CHECK(values.at<double>(key1) == 1.0);
+  }
+  {
+    Values values = { {key1, genericValue(poseA)}, {key2, genericValue(poseB)} };
+    EXPECT_LONGS_EQUAL(2, values.size());
+    EXPECT(assert_equal(values.at<Pose2>(key1), poseA));
+    EXPECT(assert_equal(values.at<Pose3>(key2), poseB));
+  }
+  // Test exception: duplicated key:
+  {
+    Values values;
+    CHECK_EXCEPTION((values = {
+      {key1, genericValue(poseA)},
+      {key2, genericValue(poseB)},
+      {key1, genericValue(poseC)} 
+      }), std::exception);
+  }
+}
+
+
 /* ************************************************************************* */
 int main() { TestResult tr; return TestRegistry::runAllTests(tr); }
 /* ************************************************************************* */