Introduced 'assertion-like' feature to 'ICE_ASSERT_CORE' in constexpr contexts.

* It will now fail compilation when the check fails.
* There is no possibility to give a message yes.

Author: Dandielo

source/code/core/core/public/ice/assert_core.hxx

@@ -8,24 +8,42 @@
 #include <cassert>
 #undef assert
 
+namespace ice::detail
+{
+
+    // The following function will fail to access element at index [2] only in constexpr scenarios and when the expression is false.
+    // This is good enough for us to create an assertion macro for constexpr and non-constexpr cases.
+    constexpr char _iceshard_constexpr_assert(bool v) noexcept
+    {
+        int cev = std::is_constant_evaluated();
+        char constexpr_assert_failure[2]{ };
+        return constexpr_assert_failure[!v + cev];
+    };
+
+} // namespace ice::detail::assert
+
 #if ISP_WINDOWS
 
 #define ICE_ASSERT_CORE(expression) do { if (std::is_constant_evaluated() == false) { \
         (void)(                                                                                 \
             (!!(expression)) ||                                                                 \
             (_wassert(_CRT_WIDE(#expression), _CRT_WIDE(__FILE__), (unsigned)(__LINE__)), 0)    \
-        ); } } while(false)
+        ); } else { ice::detail::_iceshard_constexpr_assert(expression); } } while(false)
 
 #elif ISP_WEBAPP || ISP_LINUX
 
-#define ICE_ASSERT_CORE(expression) ((expression) \
-    ? (void)0 \
-    : __assert_fail(#expression, __FILE__, __LINE__, __PRETTY_FUNCTION__))
+#define ICE_ASSERT_CORE(expression) do { if (std::is_constant_evaluated() == false) { \
+    ((expression) \
+        ? (void)0 \
+        : __assert_fail(#expression, __FILE__, __LINE__, __PRETTY_FUNCTION__)); \
+    } else { ice::detail::_iceshard_constexpr_assert(expression); } } while(false)
 
 #else
 
-#define ICE_ASSERT_CORE(expression) ((expression) \
-    ? __assert_no_op \
-    : __assert2(__FILE__, __LINE__, __PRETTY_FUNCTION__, #expression))
+#define ICE_ASSERT_CORE(expression) do { if (std::is_constant_evaluated() == false) { \
+    ((expression) \
+        ? __assert_no_op \
+        : __assert2(__FILE__, __LINE__, __PRETTY_FUNCTION__, #expression)); \
+    } else { ice::detail::_iceshard_constexpr_assert(expression); } } while(false)
 
 #endif

source/code/core/core/public/ice/shard.hxx

@@ -238,11 +238,7 @@ namespace ice
         ice::Shard result{ };
         ice::ShardID const id = ice::shardid(definition);
 
-        if (std::is_constant_evaluated() == false)
-        {
-            ICE_ASSERT_CORE(id.payload == ice::Constant_ShardPayloadID<T> || id.payload == ice::ShardPayloadID_NotSet);
-        }
-
+        ICE_ASSERT_CORE(id.payload == ice::Constant_ShardPayloadID<T> || id.payload == ice::ShardPayloadID_NotSet);
         if (id.payload == ice::Constant_ShardPayloadID<T> || id.payload == ice::ShardPayloadID_NotSet)
         {
             result.id = id;
@@ -257,11 +253,7 @@ namespace ice
     {
         ice::Shard result{ };
 
-        if (std::is_constant_evaluated() == false)
-        {
-            ICE_ASSERT_CORE(id.payload == ice::Constant_ShardPayloadID<T> || id.payload == ice::ShardPayloadID_NotSet);
-        }
-
+        ICE_ASSERT_CORE(id.payload == ice::Constant_ShardPayloadID<T> || id.payload == ice::ShardPayloadID_NotSet);
         if (id.payload == ice::Constant_ShardPayloadID<T> || id.payload == ice::ShardPayloadID_NotSet)
         {
             result.id = id;

source/code/systems/resource_system/public/ice/uri.hxx

@@ -83,12 +83,9 @@ namespace ice
             if (uri[0] == '/' && uri[1] == '/')
             {
                 ice::ucount const authority_end = ice::string::find_first_of(uri, '/', 2);
+                ICE_ASSERT_CORE(authority_end != ice::String_NPos);
                 if (authority_end == ice::String_NPos)
                 {
-                    if (std::is_constant_evaluated())
-                    {
-                        throw "Invalid URI definition! Do not use '//' without defining a host name!";
-                    }
                     return false;
                 }