Use niche in option

1 files changed, 33 insertions, 0 deletions

diff --git a/asl/tests/option_tests.cpp b/asl/tests/option_tests.cpp
index 4c65892..8b98c99 100644
--- a/asl/tests/option_tests.cpp
+++ b/asl/tests/option_tests.cpp
@@ -5,6 +5,25 @@
 class Base {};

 class Derived : public Base {};

 

+struct NonZero

+{

+    int value;

+

+    constexpr explicit NonZero(int x) : value(x)

+    {

+        ASL_ASSERT(x != 0);

+    }

+

+    constexpr explicit NonZero(asl::niche) : value(0) {}

+

+    constexpr bool operator==(asl::niche) const { return value == 0; }

+};

+static_assert(asl::has_niche<NonZero>);

+static_assert(!asl::has_niche<int>);

+

+static_assert(sizeof(asl::option<int>) > sizeof(int));

+static_assert(sizeof(asl::option<NonZero>) == sizeof(NonZero));

+

 static_assert(!asl::is_option<int>);
 static_assert(asl::is_option<asl::option<int>>);

 static_assert(asl::is_option<const asl::option<int>>);

@@ -276,3 +295,17 @@ ASL_TEST(or_else)
     ASL_TEST_ASSERT(b2.has_value());

     ASL_TEST_EXPECT(b2.value() == 12);

 }

+

+ASL_TEST(niche)

+{

+    asl::option<NonZero> opt;

+    ASL_TEST_EXPECT(!opt.has_value());

+

+    asl::option<NonZero> opt2(2);

+    ASL_TEST_EXPECT(opt2.has_value());

+    ASL_TEST_EXPECT(opt2.value().value == 2);

+

+    opt = opt2;

+    ASL_TEST_EXPECT(opt2.has_value());

+    ASL_TEST_EXPECT(opt2.value().value == 2);

+}