From abd3c0c85a0ac49c6ccdd1d6ea684a139a4c264a Mon Sep 17 00:00:00 2001
From: Francesco Biscani <bluescarni@gmail.com>
Date: Sun, 5 Nov 2023 12:08:12 +0100
Subject: [PATCH] Additional testing for relu/relup.

---
 test/relu.cpp | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/test/relu.cpp b/test/relu.cpp
index 5e57682ec..51e72c134 100644
--- a/test/relu.cpp
+++ b/test/relu.cpp
@@ -8,6 +8,7 @@
 
 #include <heyoka/config.hpp>
 
+#include <functional>
 #include <limits>
 #include <random>
 #include <sstream>
@@ -167,6 +168,32 @@ TEST_CASE("names")
     }
 }
 
+// Test to check that equality, hashing and less-than, which take into account
+// the function name, behave correctly when changing slope.
+TEST_CASE("hash eq lt")
+{
+    auto [x, y] = make_vars("x", "y");
+
+    REQUIRE(relu(x + y) != relu(x + y, 0.01));
+    REQUIRE(relup(x + y) != relup(x + y, 0.01));
+    REQUIRE(relu(x + y, 0.02) != relu(x + y, 0.01));
+    REQUIRE(relup(x + y, 0.02) != relup(x + y, 0.01));
+    REQUIRE((std::get<func>(relu(x + y).value()) < std::get<func>(relu(x + y, 0.01).value())
+             || std::get<func>(relu(x + y, 0.01).value()) < std::get<func>(relu(x + y).value())));
+    REQUIRE((std::get<func>(relup(x + y).value()) < std::get<func>(relup(x + y, 0.01).value())
+             || std::get<func>(relup(x + y, 0.01).value()) < std::get<func>(relup(x + y).value())));
+    REQUIRE((std::get<func>(relu(x + y, 0.02).value()) < std::get<func>(relu(x + y, 0.01).value())
+             || std::get<func>(relu(x + y, 0.01).value()) < std::get<func>(relu(x + y, 0.02).value())));
+    REQUIRE((std::get<func>(relup(x + y, 0.02).value()) < std::get<func>(relup(x + y, 0.01).value())
+             || std::get<func>(relup(x + y, 0.01).value()) < std::get<func>(relup(x + y, 0.02).value())));
+
+    // Of course, not 100% guaranteed but hopefully very likely.
+    REQUIRE(std::hash<expression>{}(relu(x + y)) != std::hash<expression>{}(relu(x + y, 0.01)));
+    REQUIRE(std::hash<expression>{}(relup(x + y)) != std::hash<expression>{}(relup(x + y, 0.01)));
+    REQUIRE(std::hash<expression>{}(relu(x + y, 0.02)) != std::hash<expression>{}(relu(x + y, 0.01)));
+    REQUIRE(std::hash<expression>{}(relup(x + y, 0.02)) != std::hash<expression>{}(relup(x + y, 0.01)));
+}
+
 TEST_CASE("invalid slopes")
 {
     using Catch::Matchers::Message;