Add test section for total_greater

Author: Morwenn

tests/CMakeLists.txt

@@ -187,7 +187,7 @@ add_executable(main-tests
     comparators/flip_not.cpp
     comparators/natural_less.cpp
     comparators/projection_compare.cpp
-    comparators/total_less.cpp
+    comparators/total_order.cpp
     comparators/transparent_comparators.cpp
 
     # Distributions tests

tests/comparators/total_less.cpp

@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2016-2026 Morwenn
+ * SPDX-License-Identifier: MIT
+ */
+#include <cmath>
+#include <limits>
+#include <catch2/catch_test_macros.hpp>
+#include <cpp-sort/comparators/total_greater.h>
+#include <cpp-sort/comparators/total_less.h>
+#include <cpp-sort/sorters/heap_sorter.h>
+
+TEST_CASE( "IEEE 754 totalOrder implementation", "[comparison]" )
+{
+    constexpr double nan = std::numeric_limits<double>::quiet_NaN();
+    constexpr double inf = std::numeric_limits<double>::infinity();
+
+    double array[] = { +1.0, +inf, -1.0, -nan, +0.0, -inf, +nan, -0.0 };
+
+    SECTION( "total_less" )
+    {
+        cppsort::heap_sort(array, cppsort::total_less);
+
+        // Check for IEEE 754 totalOrder,
+        // ignore quiet vs. signaling NaNs
+        CHECK( std::isnan(array[0]) );
+        CHECK( std::signbit(array[0]) );
+        CHECK( std::isinf(array[1]) );
+        CHECK( std::signbit(array[1]) );
+        CHECK( array[2] == -1.0 );
+        CHECK( array[3] == 0.0 );
+        CHECK( std::signbit(array[3]) );
+        CHECK( array[4] == 0.0 );
+        CHECK( not std::signbit(array[4]) );
+        CHECK( array[5] == +1.0 );
+        CHECK( std::isinf(array[6]) );
+        CHECK( not std::signbit(array[6]) );
+        CHECK( std::isnan(array[7]) );
+        CHECK( not std::signbit(array[7]) );
+    }
+
+    SECTION( "total_greater" )
+    {
+        cppsort::heap_sort(array, cppsort::total_greater);
+
+        // Check for IEEE 754 totalOrder,
+        // ignore quiet vs. signaling NaNs
+        CHECK( not std::signbit(array[0]) );
+        CHECK( std::isnan(array[0]) );
+        CHECK( std::isinf(array[1]) );
+        CHECK( not std::signbit(array[1]) );
+        CHECK( array[2] == +1.0 );
+        CHECK( array[3] == 0.0 );
+        CHECK( not std::signbit(array[3]) );
+        CHECK( array[4] == 0.0 );
+        CHECK( std::signbit(array[4]) );
+        CHECK( array[5] == -1.0 );
+        CHECK( std::isinf(array[6]) );
+        CHECK( std::signbit(array[6]) );
+        CHECK( std::isnan(array[7]) );
+        CHECK( std::signbit(array[7]) );
+    }
+}