From be35a267c29a7cd86a2094450ad96a2114ca84d1 Mon Sep 17 00:00:00 2001
From: Stefan Dragnev <stefan@scanbot.io>
Date: Mon, 17 May 2021 12:26:32 +0200
Subject: [PATCH] add fixed_shape::operator==

---
 include/xtensor/xstorage.hpp | 14 ++++++++++++++
 test/test_xbuilder.cpp       |  8 --------
 test/test_xstorage.cpp       | 16 +++++++++++++---
 3 files changed, 27 insertions(+), 11 deletions(-)

diff --git a/include/xtensor/xstorage.hpp b/include/xtensor/xstorage.hpp
index f43e75049..234012395 100644
--- a/include/xtensor/xstorage.hpp
+++ b/include/xtensor/xstorage.hpp
@@ -1692,6 +1692,19 @@ namespace xt
             return sizeof...(X) == 0;
         }
 
+        template <std::size_t... Y>
+        XTENSOR_FIXED_SHAPE_CONSTEXPR bool operator==(const fixed_shape<Y...>& b) const {
+            if (size() != b.size()) {
+                return false;
+            }
+            for (std::size_t i = 0; i < size(); ++i) {
+                if ((*this)[i] != b[i]) {
+                    return false;
+                }
+            }
+            return true;
+        }
+
     private:
 
          XTENSOR_CONSTEXPR_ENHANCED_STATIC cast_type m_array = cast_type({X...});
@@ -1702,6 +1715,7 @@ namespace xt
     constexpr typename fixed_shape<X...>::cast_type fixed_shape<X...>::m_array;
 #endif
 
+
 #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 0aa86cf16..a03cc131e 100644
--- a/test/test_xbuilder.cpp
+++ b/test/test_xbuilder.cpp
@@ -380,14 +380,6 @@ 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_xstorage.cpp b/test/test_xstorage.cpp
index 54ac95e2a..fd9c1d5b7 100644
--- a/test/test_xstorage.cpp
+++ b/test/test_xstorage.cpp
@@ -207,7 +207,7 @@ namespace xt
         svector_type e(src);
         EXPECT_EQ(size_t(10), d.size());
         EXPECT_EQ(size_t(1), d[2]);
-        
+
         svector_type f = { 1, 2, 3, 4 };
         EXPECT_EQ(size_t(4), f.size());
         EXPECT_EQ(size_t(3), f[2]);
@@ -221,7 +221,7 @@ namespace xt
     TEST(svector, assign)
     {
         svector_type a = { 1, 2, 3, 4 };
-        
+
         svector_type src1(10, 2);
         a = src1;
         EXPECT_EQ(size_t(10), a.size());
@@ -332,7 +332,7 @@ namespace xt
             EXPECT_EQ(i, a[i]);
         }
     }
-    
+
     TEST(fixed_shape, fixed_shape)
     {
         fixed_shape<3, 4, 5> af;
@@ -344,4 +344,14 @@ namespace xt
         EXPECT_EQ(a.front(), size_t(3));
         EXPECT_EQ(a.size(), size_t(3));
     }
+
+    TEST(fixed_shape, operator_eq)
+    {
+        fixed_shape<2, 3> a, b;
+        fixed_shape<5> c;
+        fixed_shape<2, 4> d;
+        EXPECT_TRUE(a == b);
+        EXPECT_FALSE(a == c);
+        EXPECT_FALSE(a == d);
+    }
 }