Add ADL swap test

test/adl/swap.c++

@@ -0,0 +1,41 @@
+// Wheels - various C++ utilities
+//
+// Written in 2013 by Martinho Fernandes <[email protected]>
+//
+// To the extent possible under law, the author(s) have dedicated all copyright and related
+// and neighboring rights to this software to the public domain worldwide. This software is
+// distributed without any warranty.
+//
+// You should have received a copy of the CC0 Public Domain Dedication along with this software.
+// If not, see <http://creativecommons.org/publicdomain/zero/1.0/>
+
+// ADL swap tests
+
+#include <wheels/adl/swap.h++>
+
+#include <catch.h++>
+
+namespace test {
+    struct foo { int x; };
+
+    void swap(foo& a, foo& b) { a.x += 1; b.x += 2; }
+} // namespace test
+
+TEST_CASE("adl/swap", "adl::swap tests") {
+    SECTION("custom", "") {
+        test::foo a = { 16 };
+        test::foo b = { 21 };
+        wheels::adl::swap(a, b);
+        CHECK(a.x == 17);
+        CHECK(b.x == 23);
+    }
+    SECTION("default", "") {
+        int a = 17;
+        int b = 23;
+        wheels::adl::swap(a, b);
+        CHECK(a == 23);
+        CHECK(b == 17);
+    }
+}
+
+