Add Maybe.equals when inner type is equatable.

test/unit/stdlib/collections/maybe.c3

@@ -0,0 +1,21 @@
+module maybetest @test;
+
+import std::collections::maybe;
+import std::core::types;
+
+alias maybeint = maybe::value{int};
+
+struct Unequatable { int value; }
+
+alias MaybeUnequatable = maybe::Maybe{Unequatable};
+
+fn void test_equals() @test
+{
+	$assert(!types::is_equatable_type(MaybeUnequatable));
+	assert(maybeint(1) == maybeint(1));
+	assert(maybeint(0) == maybeint(0));
+	assert(maybeint(0) != maybeint(1));
+	assert(maybeint(1) != maybeint(0));
+	assert(maybeint(0) != maybe::EMPTY{int});
+	assert(maybe::EMPTY{int} != maybeint(0));
+}