refactor: Clean up import statements and add new tests for primitive conversions

Signed-off-by: FrozenlemonTee <1115306170@qq.com>

Author: FrozenLemonTee

tests/basic/conversion/primitive/test_primitive_casts.cpp

@@ -0,0 +1,49 @@
+#include <gtest/gtest.h>
+#include <limits>
+
+import mcpplibs.primitives.underlying;
+
+#include "../../support/conversion_box_types.hpp"
+
+import mcpplibs.primitives.conversion;
+import mcpplibs.primitives.policy;
+import mcpplibs.primitives.primitive;
+
+using namespace mcpplibs::primitives;
+using namespace mcpplibs::primitives::test_support::conversion;
+
+TEST(ConversionPrimitiveTest, CheckedCastBetweenPrimitivesUsesRepBridge) {
+  using src_t =
+      primitive<SignedBox, policy::value::checked, policy::error::expected>;
+  using dest_t =
+      primitive<UnsignedBox, policy::value::checked, policy::error::expected>;
+
+  auto const ok = conversion::checked_cast<dest_t>(src_t{SignedBox{42}});
+  ASSERT_TRUE(ok.has_value());
+  EXPECT_EQ(ok->load().value, 42);
+
+  auto const bad = conversion::checked_cast<dest_t>(src_t{SignedBox{-1}});
+  ASSERT_FALSE(bad.has_value());
+  EXPECT_EQ(bad.error(), conversion::risk::kind::underflow);
+}
+
+TEST(ConversionPrimitiveTest,
+     TruncatingAndExactCastBetweenPrimitivesFollowUnderlyingRules) {
+  using float_t =
+      primitive<FloatBox, policy::value::checked, policy::error::expected>;
+  using signed_t =
+      primitive<SignedBox, policy::value::checked, policy::error::expected>;
+
+  auto const truncated = conversion::truncating_cast<signed_t>(
+      float_t{FloatBox{12.75}});
+  EXPECT_EQ(truncated.load().value, 12);
+
+  auto const exact = conversion::exact_cast<signed_t>(float_t{FloatBox{12.0}});
+  ASSERT_TRUE(exact.has_value());
+  EXPECT_EQ(exact->load().value, 12);
+
+  auto const bad_exact = conversion::exact_cast<signed_t>(
+      float_t{FloatBox{std::numeric_limits<double>::quiet_NaN()}});
+  ASSERT_FALSE(bad_exact.has_value());
+  EXPECT_EQ(bad_exact.error(), conversion::risk::kind::domain_error);
+}

tests/basic/conversion/primitive_underlying/test_mixed_casts.cpp

@@ -0,0 +1,41 @@
+#include <gtest/gtest.h>
+
+import mcpplibs.primitives.underlying;
+
+#include "../../support/conversion_box_types.hpp"
+
+import mcpplibs.primitives.conversion;
+import mcpplibs.primitives.policy;
+import mcpplibs.primitives.primitive;
+
+using namespace mcpplibs::primitives;
+using namespace mcpplibs::primitives::test_support::conversion;
+
+TEST(ConversionPrimitiveUnderlyingTest,
+     CheckedCastSupportsUnderlyingToPrimitiveBridge) {
+  using value_t =
+      primitive<UnsignedBox, policy::value::checked, policy::error::expected>;
+
+  auto const ok = conversion::checked_cast<value_t>(SignedBox{42});
+  ASSERT_TRUE(ok.has_value());
+  EXPECT_EQ(ok->load().value, 42);
+
+  auto const bad = conversion::checked_cast<value_t>(SignedBox{-1});
+  ASSERT_FALSE(bad.has_value());
+  EXPECT_EQ(bad.error(), conversion::risk::kind::underflow);
+}
+
+TEST(ConversionPrimitiveUnderlyingTest,
+     PrimitiveToUnderlyingCastsReuseUnderlyingConversion) {
+  using value_t =
+      primitive<SignedBox, policy::value::checked, policy::error::expected>;
+
+  auto const ok = conversion::checked_cast<UnsignedBox>(value_t{SignedBox{42}});
+  ASSERT_TRUE(ok.has_value());
+  EXPECT_EQ(ok->value, 42);
+
+  auto const truncated =
+      conversion::truncating_cast<SignedBox>(primitive<FloatBox>{
+          FloatBox{12.75}});
+  EXPECT_EQ(truncated.value, 12);
+}

tests/basic/conversion/traits/test_numeric_risk.cpp

@@ -7,7 +7,6 @@ import mcpplibs.primitives.conversion.underlying;
 import mcpplibs.primitives.underlying;
 
 #include "../../support/conversion_box_types.hpp"
-
 using namespace mcpplibs::primitives;
 using namespace mcpplibs::primitives::test_support::conversion;
 

tests/basic/conversion/underlying/test_underlying_casts.cpp

@@ -6,7 +6,6 @@ import mcpplibs.primitives.conversion.traits;
 import mcpplibs.primitives.conversion.underlying;
 
 #include "../../support/conversion_box_types.hpp"
-
 using namespace mcpplibs::primitives;
 using namespace mcpplibs::primitives::test_support::conversion;
 

tests/basic/primitive/traits/test_meta_traits.cpp

@@ -5,7 +5,6 @@ import mcpplibs.primitives.primitive;
 import mcpplibs.primitives.policy;
 
 #include "../../support/underlying_custom_types.hpp"
-
 using namespace mcpplibs::primitives;
 
 TEST(PrimitiveTraitsTest, MetaTraitsExposeValueTypeAndPrimitiveMetadata) {

tests/basic/underlying/common_rep/test_common_rep_and_type_policy.cpp

@@ -6,7 +6,6 @@ import mcpplibs.primitives.policy;
 import mcpplibs.primitives.operations.impl;
 
 #include "../../support/underlying_custom_types.hpp"
-
 using namespace mcpplibs::primitives;
 using namespace mcpplibs::primitives::test_support::underlying;
 

tests/basic/underlying/traits/test_concepts_and_registration.cpp

@@ -3,7 +3,6 @@
 import mcpplibs.primitives.underlying;
 
 #include "../../support/underlying_custom_types.hpp"
-
 using namespace mcpplibs::primitives;
 using namespace mcpplibs::primitives::test_support::underlying;