From 3ca1925e1bbabe5e7d95f16b9bd63181e5852067 Mon Sep 17 00:00:00 2001
From: Mykola Vankovych <mykola.vankovych1@gmail.com>
Date: Wed, 7 Apr 2021 21:18:21 +0200
Subject: [PATCH] adding == operator to fixed_shape.

---
 include/xtensor/xstorage.hpp | 12 ++++++++++++
 test/test_xbuilder.cpp       |  8 --------
 test/test_xreducer.cpp       |  8 --------
 3 files changed, 12 insertions(+), 16 deletions(-)

diff --git a/include/xtensor/xstorage.hpp b/include/xtensor/xstorage.hpp
index 686cb7176..56f7a360a 100644
--- a/include/xtensor/xstorage.hpp
+++ b/include/xtensor/xstorage.hpp
@@ -1697,6 +1697,18 @@ namespace xt
     constexpr typename fixed_shape<X...>::cast_type fixed_shape<X...>::m_array;
 #endif
 
+    template <std::size_t... X1, std::size_t... X2>
+    XTENSOR_FIXED_SHAPE_CONSTEXPR bool operator==(const fixed_shape<X1...>&, const fixed_shape<X2...>&)
+    {
+        return std::is_same<fixed_shape<X1...>, fixed_shape<X2...>>::value;
+    }
+
+    template <std::size_t... X1, std::size_t... X2>
+    XTENSOR_FIXED_SHAPE_CONSTEXPR bool operator!=(const fixed_shape<X1...>& lhs, const fixed_shape<X2...>& rhs)
+    {
+        return !(lhs == rhs);
+    }
+
 #undef XTENSOR_FIXED_SHAPE_CONSTEXPR
 
     template <class E, std::ptrdiff_t Start, std::ptrdiff_t End = -1>
diff --git a/test/test_xbuilder.cpp b/test/test_xbuilder.cpp
index 042e89793..4ce275cb2 100644
--- a/test/test_xbuilder.cpp
+++ b/test/test_xbuilder.cpp
@@ -361,14 +361,6 @@ namespace xt
         XT_EXPECT_ANY_THROW(xt::concatenate(xt::xtuple(fa, ta)));
     }
 
-    template <std::size_t... I, std::size_t... J>
-    bool operator==(fixed_shape<I...>, fixed_shape<J...>)
-    {
-        std::array<std::size_t, sizeof...(I)> ix = {I...};
-        std::array<std::size_t, sizeof...(J)> jx = {J...};
-        return sizeof...(J) == sizeof...(I) && std::equal(ix.begin(), ix.end(), jx.begin());
-    }
-
 #ifndef VS_SKIP_CONCATENATE_FIXED
     // This test mimics the relevant parts of `TEST(xbuilder, concatenate)`
     TEST(xbuilder, concatenate_fixed)
diff --git a/test/test_xreducer.cpp b/test/test_xreducer.cpp
index 13081faeb..4e8fd18e6 100644
--- a/test/test_xreducer.cpp
+++ b/test/test_xreducer.cpp
@@ -939,14 +939,6 @@ namespace xt
         EXPECT_EQ(b.dimension(), 0u);
         EXPECT_EQ(minmax(b)(), (A{1.2, 1.2}));
     }
-    
-    template <std::size_t... I, std::size_t... J>
-    bool operator==(fixed_shape<I...>, fixed_shape<J...>)
-    {
-        std::array<std::size_t, sizeof...(I)> ix = {I...};
-        std::array<std::size_t, sizeof...(J)> jx = {J...};
-        return sizeof...(J) == sizeof...(I) && std::equal(ix.begin(), ix.end(), jx.begin());
-    }
 
     TEST(xreducer, keep_dims)
     {