Move CppTypeToScalarType to torch/headeronly

[ghstack-poisoned]

c10/core/ScalarType.h

@@ -33,20 +33,6 @@ namespace c10 {
 // See [dtype Macros note] in torch/headeronly/core/ScalarType.h
 // regarding macros.
 
-template <typename T>
-struct CppTypeToScalarType;
-
-#define SPECIALIZE_CppTypeToScalarType(cpp_type, scalar_type)                  \
-  template <>                                                                  \
-  struct CppTypeToScalarType<cpp_type>                                         \
-      : std::                                                                  \
-            integral_constant<c10::ScalarType, c10::ScalarType::scalar_type> { \
-  };
-
-AT_FORALL_SCALAR_TYPES_WITH_COMPLEX_AND_QINTS(SPECIALIZE_CppTypeToScalarType)
-
-#undef SPECIALIZE_CppTypeToScalarType
-
 #define DEFINE_CONSTANT(_, name) \
   constexpr ScalarType k##name = ScalarType::name;
 

test/cpp/aoti_abi_check/test_scalartype.cpp

@@ -13,6 +13,17 @@ TEST(TestScalarType, ScalarTypeToCPPTypeT) {
 #undef DEFINE_CHECK
 }
 
+TEST(TestScalarType, CppTypeToScalarType) {
+  using c10::CppTypeToScalarType;
+  using torch::headeronly::ScalarType;
+
+#define DEFINE_CHECK(TYPE, SCALARTYPE) \
+  EXPECT_EQ(CppTypeToScalarType<TYPE>::value, ScalarType::SCALARTYPE);
+
+  AT_FORALL_SCALAR_TYPES_WITH_COMPLEX_AND_QINTS(DEFINE_CHECK);
+#undef DEFINE_CHECK
+}
+
 #define DEFINE_CHECK(TYPE, SCALARTYPE)                                       \
   {                                                                          \
     EXPECT_EQ(                                                               \

torch/header_only_apis.txt

@@ -161,6 +161,7 @@ COMPILE_TIME_MAX_DEVICE_TYPES
 NumScalarTypes
 ScalarType
 # dummy_int1_7_t, dummy_uint1_7_t tested through ScalarType
+CppTypeToScalarType
 ScalarTypeToCPPTypeT
 AT_FORALL_SCALAR_TYPES_WITH_COMPLEX_EXCEPT_COMPLEX_HALF_F8NZ
 AT_FORALL_SCALAR_TYPES_WITH_COMPLEX

torch/headeronly/core/ScalarType.h

@@ -266,6 +266,21 @@ enum class ScalarType : int8_t {
 constexpr uint16_t NumScalarTypes =
     static_cast<uint16_t>(ScalarType::NumOptions);
 
+// Map from C++ type to ScalarType enum
+template <typename T>
+struct CppTypeToScalarType;
+
+#define SPECIALIZE_CppTypeToScalarType(cpp_type, scalar_type)                  \
+  template <>                                                                  \
+  struct CppTypeToScalarType<cpp_type>                                         \
+      : std::                                                                  \
+            integral_constant<c10::ScalarType, c10::ScalarType::scalar_type> { \
+  };
+
+AT_FORALL_SCALAR_TYPES_WITH_COMPLEX_AND_QINTS(SPECIALIZE_CppTypeToScalarType)
+
+#undef SPECIALIZE_CppTypeToScalarType
+
 namespace impl {
 
 // These are used to map ScalarTypes to C++ types.
@@ -340,6 +355,7 @@ inline ScalarType toUnderlying(ScalarType t) {
 } // namespace c10
 
 HIDDEN_NAMESPACE_BEGIN(torch, headeronly)
+using c10::CppTypeToScalarType;
 using c10::dummy_int1_7_t;
 using c10::dummy_uint1_7_t;
 using c10::NumScalarTypes;