From 50fda2d100bdf653fe57817db496ac13c7c8d048 Mon Sep 17 00:00:00 2001
From: =?utf8?q?=EB=B0=95=EC=A2=85=ED=98=84/=EB=8F=99=EC=9E=91=EC=A0=9C?=
 =?utf8?q?=EC=96=B4Lab=28SR=29/Staff=20Engineer/=EC=82=BC=EC=84=B1?=
 =?utf8?q?=EC=A0=84=EC=9E=90?= <jh1302.park@samsung.com>
Date: Thu, 19 Jul 2018 10:15:59 +0900
Subject: [PATCH] [nest] Overload 'operator+' over nest expressions (#712)

This commit introduce 'operator+' overloading to make it easy to
construct 'ADD' expression in nest IR.

Signed-off-by: Jonghyun Park <jh1302.park@samsung.com>
---
 contrib/nest/include/nest/Expr.h |  2 ++
 contrib/nest/src/Expr.cpp        |  6 ++++++
 contrib/nest/src/Expr.test.cpp   | 27 +++++++++++++++++++++++++++
 3 files changed, 35 insertions(+)
 create mode 100644 contrib/nest/src/Expr.cpp
 create mode 100644 contrib/nest/src/Expr.test.cpp

diff --git a/contrib/nest/include/nest/Expr.h b/contrib/nest/include/nest/Expr.h
index 9fc09cb..8fef2b1 100644
--- a/contrib/nest/include/nest/Expr.h
+++ b/contrib/nest/include/nest/Expr.h
@@ -17,4 +17,6 @@ using Expr = std::shared_ptr<nest::expr::Node>;
 
 } // namespace nest
 
+nest::Expr operator+(const nest::Expr &, const nest::Expr &);
+
 #endif // __NEST_EXPR_H__
diff --git a/contrib/nest/src/Expr.cpp b/contrib/nest/src/Expr.cpp
new file mode 100644
index 0000000..46e9b41
--- /dev/null
+++ b/contrib/nest/src/Expr.cpp
@@ -0,0 +1,6 @@
+#include "nest/Expr.h"
+
+nest::Expr operator+(const nest::Expr &lhs, const nest::Expr &rhs)
+{
+  return std::make_shared<nest::expr::AddNode>(lhs, rhs);
+}
diff --git a/contrib/nest/src/Expr.test.cpp b/contrib/nest/src/Expr.test.cpp
new file mode 100644
index 0000000..de469ca
--- /dev/null
+++ b/contrib/nest/src/Expr.test.cpp
@@ -0,0 +1,27 @@
+#include "nest/Expr.h"
+
+#include <memory>
+
+#include <gtest/gtest.h>
+
+namespace
+{
+struct DummyNode final : public nest::expr::Node
+{
+};
+}
+
+TEST(EXPR, operator_sum)
+{
+  auto left = std::make_shared<DummyNode>();
+  auto right = std::make_shared<DummyNode>();
+
+  auto expr = left + right;
+
+  ASSERT_NE(expr->asAdd(), nullptr);
+
+  auto add = expr->asAdd();
+
+  ASSERT_EQ(add->lhs().get(), left.get());
+  ASSERT_EQ(add->rhs().get(), right.get());
+}
-- 
2.7.4