Add tests for generalized callables

Author: Morwenn

tests/CMakeLists.txt

@@ -79,14 +79,22 @@ add_executable(cxx_98_tests
 configure_tests(cxx_98_tests)
 target_compile_features(cxx_98_tests PRIVATE cxx_std_98)
 
-# Tests that require C++11 support
+# Tests requiring C++11 support
 add_executable(cxx_11_tests
     main.cpp
     cxx_11_tests.cpp
 )
 configure_tests(cxx_11_tests)
 target_compile_features(cxx_11_tests PRIVATE cxx_std_11)
 
+# Tests requiring C++17 support
+add_executable(cxx_17_tests
+    main.cpp
+    cxx_17_tests.cpp
+)
+configure_tests(cxx_17_tests)
+target_compile_features(cxx_17_tests PRIVATE cxx_std_17)
+
 # Windows-specific tests
 if (WIN32)
     add_executable(windows_tests
@@ -102,6 +110,7 @@ include(Catch)
 
 catch_discover_tests(cxx_98_tests)
 catch_discover_tests(cxx_11_tests)
+catch_discover_tests(cxx_17_tests)
 if (WIN32)
     catch_discover_tests(windows_tests)
 endif()

tests/cxx_17_tests.cpp

@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2011 Fuji, Goro (gfx) <[email protected]>.
+ * Copyright (c) 2019 Morwenn.
+ *
+ * SPDX-License-Identifier: MIT
+ */
+#include <algorithm>
+#include <functional>
+#include <numeric>
+#include <random>
+#include <vector>
+#include <catch2/catch.hpp>
+#include <gfx/timsort.hpp>
+
+namespace
+{
+    struct wrapper {
+        wrapper() = default;
+        wrapper(wrapper const&) = default;
+        wrapper(wrapper&&) = default;
+
+        wrapper(int val) : value(val) {
+        }
+
+        wrapper& operator=(wrapper const&) = default;
+        wrapper& operator=(wrapper&&) = default;
+
+        wrapper& operator=(int val) {
+            value = val;
+            return *this;
+        }
+
+        bool compare_to(wrapper const& other) const {
+            return value < other.value;
+        }
+
+        int value = 0;
+    };
+}
+
+#ifdef __cpp_lib_invoke
+
+TEST_CASE( "generalized callables" ) {
+    std::vector<wrapper> vec(50);
+    std::iota(vec.begin(), vec.end(), -25);
+    std::mt19937 gen(123456); // fixed seed is enough
+    std::shuffle(vec.begin(), vec.end(), gen);
+
+    SECTION( "for comparisons" ) {
+        gfx::timsort(vec, &wrapper::compare_to);
+        CHECK(std::is_sorted(vec.begin(), vec.end(), [](wrapper const& lhs, wrapper const& rhs) {
+            return lhs.value < rhs.value;
+        }));
+    }
+
+    SECTION( "for projections" ) {
+        gfx::timsort(vec, std::less<>{}, &wrapper::value);
+        CHECK(std::is_sorted(vec.begin(), vec.end(), [](wrapper const& lhs, wrapper const& rhs) {
+            return lhs.value < rhs.value;
+        }));
+    }
+}
+
+#endif // __cpp_lib_invoke