From 36a9d70d7cdabb71b84a4deee7c35bdc8b10a4a3 Mon Sep 17 00:00:00 2001
From: KurtisT <krt132psu@gmail.com>
Date: Thu, 9 Feb 2023 12:13:14 -0500
Subject: [PATCH] Feature/span equality operators (#670)

* feat: implement equality operator

* test: test equality operator

* feat: implement not equal operator

* test: test not equal operator

---------

Co-authored-by: Kurtis Thrush <kthrush@jlg.com>
---
 include/etl/span.h                | 36 +++++++++++++++++++++++++++++++
 test/test_span_dynamic_extent.cpp | 28 ++++++++++++++++++++++++
 test/test_span_fixed_extent.cpp   | 28 ++++++++++++++++++++++++
 3 files changed, 92 insertions(+)

diff --git a/include/etl/span.h b/include/etl/span.h
index 32f27106..bfd7a4f4 100644
--- a/include/etl/span.h
+++ b/include/etl/span.h
@@ -345,6 +345,24 @@ namespace etl
       return pbegin[i];
     }
 
+    //*************************************************************************
+    /// Compare two spans for equality.
+    //*************************************************************************
+    template <typename Type2, size_t N2, etl::enable_if_t<etl::is_same<etl::remove_cv_t<Type2>, value_type>::value, bool> = true>
+    ETL_NODISCARD ETL_CONSTEXPR bool operator==(const etl::span<Type2, N2>& other) const ETL_NOEXCEPT
+    {
+      return ((pbegin == other.pbegin) && (Extent == other.size()));
+    }
+
+    //*************************************************************************
+    /// Compare two spans for non-equality.
+    //*************************************************************************
+    template <typename Type2, size_t N2, etl::enable_if_t<etl::is_same<etl::remove_cv_t<Type2>, value_type>::value, bool> = true>
+    ETL_NODISCARD ETL_CONSTEXPR bool operator!=(const etl::span<Type2, N2>& other) const ETL_NOEXCEPT
+    {
+      return !(*this == other);
+    }
+
     //*************************************************************************
     /// Obtains a span that is a view over the first COUNT elements of this span.
     //*************************************************************************
@@ -731,6 +749,24 @@ namespace etl
       return pbegin[i];
     }
 
+    //*************************************************************************
+    /// Compare two spans for equality.
+    //*************************************************************************
+    template <typename Type2, etl::enable_if_t<etl::is_same<etl::remove_cv_t<Type2>, value_type>::value, bool> = true>
+    ETL_NODISCARD ETL_CONSTEXPR bool operator==(const etl::span<Type2>& other) const ETL_NOEXCEPT
+    {
+      return ((pbegin == other.pbegin) && (pend == other.pend));
+    }
+
+    //*************************************************************************
+    /// Compare two spans for non-equality.
+    //*************************************************************************
+    template <typename Type2, etl::enable_if_t<etl::is_same<etl::remove_cv_t<Type2>, value_type>::value, bool> = true>
+    ETL_NODISCARD ETL_CONSTEXPR bool operator!=(const etl::span<Type2>& other) const ETL_NOEXCEPT
+    {
+      return !(*this == other);
+    }
+
     //*************************************************************************
     /// Obtains a span that is a view over the first COUNT elements of this span.
     //*************************************************************************
diff --git a/test/test_span_dynamic_extent.cpp b/test/test_span_dynamic_extent.cpp
index 8223fbfd..944b991e 100644
--- a/test/test_span_dynamic_extent.cpp
+++ b/test/test_span_dynamic_extent.cpp
@@ -970,6 +970,34 @@ namespace
       }
     }
 
+    //*************************************************************************
+    TEST(test_operator_equality)
+    {
+      etl::array data1{0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
+      etl::array data2{0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
+
+      View view1{data1};
+      View view2{data1};
+      View view3{data2};
+
+      CHECK_TRUE((view1 == view2));
+      CHECK_FALSE((view1 == view3));
+    }
+
+    //*************************************************************************
+    TEST(test_operator_not_equal)
+    {
+      etl::array data1{0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
+      etl::array data2{0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
+
+      View view1{data1};
+      View view2{data1};
+      View view3{data2};
+
+      CHECK_FALSE((view1 != view2));
+      CHECK_TRUE((view1 != view3));
+    }
+
 #include "etl/private/diagnostic_pop.h"
   };
 }
diff --git a/test/test_span_fixed_extent.cpp b/test/test_span_fixed_extent.cpp
index dba32320..82b3a51f 100644
--- a/test/test_span_fixed_extent.cpp
+++ b/test/test_span_fixed_extent.cpp
@@ -960,6 +960,34 @@ namespace
       }
     }
 
+    //*************************************************************************
+    TEST(test_operator_equality)
+    {
+      etl::array data1{0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
+      etl::array data2{0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
+
+      View view1{data1};
+      View view2{data1};
+      View view3{data2};
+
+      CHECK_TRUE((view1 == view2));
+      CHECK_FALSE((view1 == view3));
+    }
+
+    //*************************************************************************
+    TEST(test_operator_not_equal)
+    {
+      etl::array data1{0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
+      etl::array data2{0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
+
+      View view1{data1};
+      View view2{data1};
+      View view3{data2};
+
+      CHECK_FALSE((view1 != view2));
+      CHECK_TRUE((view1 != view3));
+    }
+
 #include "etl/private/diagnostic_pop.h"
   };
 }