[type_traits] is_noop_convertible: remove cv

Author: iboB

include/itlib/type_traits.hpp

@@ -76,15 +76,18 @@ struct type_identity {
 };
 
 template <typename From, typename To>
-struct is_noop_convertible : std::integral_constant<bool,
-        sizeof(From) == sizeof(To)
-        && std::is_scalar<From>::value
-        && std::is_scalar<To>::value
-        && std::is_floating_point<From>::value == std::is_floating_point<To>::value
+struct is_noop_convertible {
+    using from_t = typename std::remove_cv<From>::type;
+    using to_t = typename std::remove_cv<To>::type;
+
+    static constexpr bool value = sizeof(from_t) == sizeof(to_t)
+        && std::is_scalar<from_t>::value
+        && std::is_scalar<to_t>::value
+        && std::is_floating_point<from_t>::value == std::is_floating_point<to_t>::value
         // bool -> int8 is a noop, but int8 -> bool is not
-        && (std::is_same<To, bool>::value ? std::is_same<From, bool>::value : true)
-    >
-{};
+        && (std::is_same<to_t, bool>::value ? std::is_same<from_t, bool>::value : true)
+        ;
+};
 
 #if __cplusplus >= 201700
 template <template <typename...> class Template, typename Type>

test/t-type_traits-11.cpp

@@ -35,21 +35,26 @@ struct S32 { int x; };
 
 TEST_CASE("is_noop_convertible") {
     CCHECK(itlib::is_noop_convertible<int, int>::value);
+    CCHECK(itlib::is_noop_convertible<const int, int>::value);
     CCHECK(itlib::is_noop_convertible<int, unsigned int>::value);
     CCHECK(itlib::is_noop_convertible<uint8_t, char>::value);
     CCHECK(itlib::is_noop_convertible<int8_t, char>::value);
-    CCHECK(itlib::is_noop_convertible<uint8_t, char>::value);
+    CCHECK(itlib::is_noop_convertible<uint8_t, const char>::value);
     CCHECK(itlib::is_noop_convertible<E32, int>::value);
+    CCHECK(itlib::is_noop_convertible<const E32, int>::value);
     CCHECK(itlib::is_noop_convertible<void*, size_t>::value);
     CCHECK(itlib::is_noop_convertible<void*, intptr_t>::value);
     CCHECK(itlib::is_noop_convertible<double, double>::value);
     CCHECK(itlib::is_noop_convertible<bool, bool>::value);
     CCHECK(itlib::is_noop_convertible<bool, int8_t>::value);
+    CCHECK(itlib::is_noop_convertible<bool, const bool>::value);
+    CCHECK(itlib::is_noop_convertible<const bool, bool>::value);
 
     CCHECK_FALSE(itlib::is_noop_convertible<int, float>::value);
     CCHECK_FALSE(itlib::is_noop_convertible<E32, float>::value);
     CCHECK_FALSE(itlib::is_noop_convertible<int, S32>::value);
     CCHECK_FALSE(itlib::is_noop_convertible<void*, float>::value);
     CCHECK_FALSE(itlib::is_noop_convertible<void*, double>::value);
     CCHECK_FALSE(itlib::is_noop_convertible<int8_t, bool>::value);
+    CCHECK_FALSE(itlib::is_noop_convertible<int8_t, const bool>::value);
 }