Disable warning C4275 in MSVC

include/pybind11/detail/common.h

@@ -654,12 +654,20 @@ using expand_side_effects = bool[];
 NAMESPACE_END(detail)
 
 /// C++ bindings of builtin Python exceptions
+//
+#if defined(_MSC_VER)
+#  pragma warning(push)
+#  pragma warning(disable: 4275) // warning C4275: An exported class was derived from a class that wasn't exported
+#endif
 class PYBIND11_EXPORT builtin_exception : public std::runtime_error {
 public:
     using std::runtime_error::runtime_error;
     /// Set the error using the Python C API
     virtual void set_error() const = 0;
 };
+#if defined(_MSC_VER)
+#  pragma warning(pop)
+#endif
 
 #define PYBIND11_RUNTIME_EXCEPTION(name, type) \
     class PYBIND11_EXPORT name : public builtin_exception { public: \

include/pybind11/pytypes.h

@@ -319,6 +319,10 @@ NAMESPACE_END(detail)
 /// thrown to propagate python-side errors back through C++ which can either be caught manually or
 /// else falls back to the function dispatcher (which then raises the captured error back to
 /// python).
+#if defined(_MSC_VER)
+#  pragma warning(push)
+#  pragma warning(disable: 4275) // warning C4275: An exported class was derived from a class that wasn't exported
+#endif
 class PYBIND11_EXPORT error_already_set : public std::runtime_error {
 public:
     /// Constructs a new exception from the current Python error indicator, if any.  The current
@@ -349,7 +353,9 @@ class PYBIND11_EXPORT error_already_set : public std::runtime_error {
 private:
     object type, value, trace;
 };
-
+#if defined(_MSC_VER)
+#  pragma warning(pop)
+#endif
 /** \defgroup python_builtins _
     Unless stated otherwise, the following C++ functions behave the same
     as their Python counterparts.