Move register_dtype() outside of the template

(avoid code bloat if possible)

include/pybind11/numpy.h

@@ -81,14 +81,18 @@ struct numpy_type_info {
 struct numpy_internals {
     std::unordered_map<std::type_index, numpy_type_info> registered_dtypes;
 
-    template<typename T> numpy_type_info *get_type_info(bool throw_if_missing = true) {
-        auto it = registered_dtypes.find(std::type_index(typeid(T)));
+    numpy_type_info *get_type_info(const std::type_info& tinfo, bool throw_if_missing = true) {
+        auto it = registered_dtypes.find(std::type_index(tinfo));
         if (it != registered_dtypes.end())
             return &(it->second);
         if (throw_if_missing)
-            pybind11_fail(std::string("NumPy type info missing for ") + typeid(T).name());
+            pybind11_fail(std::string("NumPy type info missing for ") + tinfo.name());
         return nullptr;
     }
+
+    template<typename T> numpy_type_info *get_type_info(bool throw_if_missing = true) {
+        return get_type_info(typeid(typename std::remove_cv<T>::type), throw_if_missing);
+    }
 };
 
 inline PYBIND11_NOINLINE void load_numpy_internals(numpy_internals* &ptr) {
@@ -686,34 +690,25 @@ struct field_descriptor {
     dtype descr;
 };
 
-template <typename T>
-struct npy_format_descriptor<T, enable_if_t<is_pod_struct<T>::value>> {
-    static PYBIND11_DESCR name() { return _("struct"); }
-
-    static pybind11::dtype dtype() {
-        return object(dtype_ptr(), true);
-    }
-
-    static std::string format() {
-        static auto format_str = get_numpy_internals().get_type_info<T>(true)->format_str;
-        return format_str;
-    }
-
-    static void register_dtype(std::initializer_list<field_descriptor> fields) {
+inline PYBIND11_NOINLINE void register_structured_dtype(
+    const std::initializer_list<field_descriptor>& fields,
+    const std::type_info& tinfo, size_t itemsize,
+    bool (*direct_converter)(PyObject *, void *&))
+{
     auto& numpy_internals = get_numpy_internals();
-        if (numpy_internals.get_type_info<T>(false))
+    if (numpy_internals.get_type_info(tinfo, false))
         pybind11_fail("NumPy: dtype is already registered");
 
     list names, formats, offsets;
     for (auto field : fields) {
         if (!field.descr)
             pybind11_fail(std::string("NumPy: unsupported field dtype: `") +
-                              field.name + "` @ " + typeid(T).name());
+                            field.name + "` @ " + tinfo.name());
         names.append(PYBIND11_STR_TYPE(field.name));
         formats.append(field.descr);
         offsets.append(pybind11::int_(field.offset));
     }
-        auto dtype_ptr = pybind11::dtype(names, formats, offsets, sizeof(T)).release().ptr();
+    auto dtype_ptr = pybind11::dtype(names, formats, offsets, itemsize).release().ptr();
 
     // There is an existing bug in NumPy (as of v1.11): trailing bytes are
     // not encoded explicitly into the format string. This will supposedly
@@ -735,20 +730,38 @@ struct npy_format_descriptor<T, enable_if_t<is_pod_struct<T>::value>> {
         oss << '=' << field.format << ':' << field.name << ':';
         offset = field.offset + field.size;
     }
-        if (sizeof(T) > offset)
-            oss << (sizeof(T) - offset) << 'x';
+    if (itemsize > offset)
+        oss << (itemsize - offset) << 'x';
     oss << '}';
     auto format_str = oss.str();
 
     // Sanity check: verify that NumPy properly parses our buffer format string
     auto& api = npy_api::get();
-        auto arr =  array(buffer_info(nullptr, sizeof(T), format_str, 1));
+    auto arr =  array(buffer_info(nullptr, itemsize, format_str, 1));
     if (!api.PyArray_EquivTypes_(dtype_ptr, arr.dtype().ptr()))
         pybind11_fail("NumPy: invalid buffer descriptor!");
 
-        auto tindex = std::type_index(typeid(T));
+    auto tindex = std::type_index(tinfo);
     numpy_internals.registered_dtypes[tindex] = { dtype_ptr, format_str };
     get_internals().direct_conversions[tindex].push_back(direct_converter);
+}
+
+template <typename T>
+struct npy_format_descriptor<T, enable_if_t<is_pod_struct<T>::value>> {
+    static PYBIND11_DESCR name() { return _("struct"); }
+
+    static pybind11::dtype dtype() {
+        return object(dtype_ptr(), true);
+    }
+
+    static std::string format() {
+        static auto format_str = get_numpy_internals().get_type_info<T>(true)->format_str;
+        return format_str;
+    }
+
+    static void register_dtype(const std::initializer_list<field_descriptor>& fields) {
+        register_structured_dtype(fields, typeid(typename std::remove_cv<T>::type),
+                                  sizeof(T), &direct_converter);
     }
 
 private: