From d9c9c2ada7a7b881ce558c819c52fb86ce15dc57 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20Robert?= <cr52@protonmail.com>
Date: Tue, 10 Dec 2024 16:31:27 +0100
Subject: [PATCH] TYP: fix type annotations for
 _CoordinateValidatorMixin._get_safe_datatype for compatibility with numpy 2.2

---
 src/gpgi/_data_types.py | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/gpgi/_data_types.py b/src/gpgi/_data_types.py
index 67843d7..62af0ef 100644
--- a/src/gpgi/_data_types.py
+++ b/src/gpgi/_data_types.py
@@ -42,8 +42,11 @@
 if TYPE_CHECKING:
     from typing import Any, Self
 
+    from numpy.typing import NDArray
+
     from gpgi._typing import FieldMap, HCIArray, Name, RealArray
 
+
 BoundarySpec = tuple[tuple[str, str, str], ...]
 
 
@@ -227,15 +230,15 @@ def _validate_coordinates(self) -> None:
 
             self.coordinates[axis] = coord.astype(coord_dtype, copy=False)
 
-    def _get_safe_datatype(self, reference: np.ndarray | None = None) -> np.dtype:
+    def _get_safe_datatype(
+        self, reference: NDArray[np.floating] | None = None
+    ) -> np.dtype[np.floating]:
         if reference is None:
             reference = self.coordinates[self.axes[0]]
         dt = reference.dtype
         if dt.kind != "f":
             raise ValueError(f"Invalid data type {dt} (expected a float dtype)")
-        # return type should already be correct but
-        # this has the benefit of convincing mypy
-        return np.dtype(dt)
+        return dt
 
 
 class Grid(_CoordinateValidatorMixin):