Add function to check that Quantity match the expected layout

Co-Authored-By: Guillaume Fraux <guillaume.fraux@epfl.ch>

Author: GardevoirX

docs/src/quantities/mass.rst

@@ -37,7 +37,7 @@ following metadata:
     - the ``"mass"`` quantity must not have any components
 
   * - properties
-    - ``"mass``
+    - ``"mass"``
     - The ``"mass"`` quantity must have a single property dimension named
       ``"mass"``, with a single entry set to ``0``.
 

docs/src/quantities/non_conservative.rst

@@ -133,7 +133,7 @@ and must have the following metadata:
   * - keys
     - ``"_"``
     - the keys must have a single dimension named ``"_"``, with a single entry
-      set to ``0``. The ``"non_conservative_force"`` quantity is always
+      set to ``0``. The ``"non_conservative_stress"`` quantity is always
       represented as a :py:class:`metatensor.torch.TensorMap` with a single
       block.
 

docs/src/quantities/velocity.rst

@@ -36,7 +36,7 @@ following metadata:
   * - components
     - ``"xyz"``
     - The ``"velocity"`` quantity must have a single component dimension named
-      ``"xyz"``, with three entries set to ``0``, ``1``, and ``2``. The position
+      ``"xyz"``, with three entries set to ``0``, ``1``, and ``2``. The velocity
       is always a 3D vector, and the order of the components is ``x, y, z``.
 
   * - properties

metatomic-core/src/kernels/mod.rs

@@ -81,6 +81,14 @@ pub struct ReferenceValue<T> {
     pub(crate) metal: OnceLock<(metal::MetalBuffer, StridedNDIndex)>,
 }
 
+impl std::fmt::Debug for ReferenceValue<i32> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("ReferenceValue")
+            .field("cpu", &self.cpu)
+            .finish()
+    }
+}
+
 impl<T> ReferenceValue<T> {
     pub(crate) fn new(cpu: ArrayD<T>) -> Self {
         Self {

metatomic-core/src/metadata.rs

@@ -3,6 +3,7 @@ use std::fmt::Write;
 
 use json::JsonValue;
 
+use crate::metadata::DType::Float32;
 use crate::{Error, Quantity};
 use crate::units::validate_unit;
 
@@ -459,6 +460,16 @@ pub enum DType {
     Float64,
 }
 
+impl std::fmt::Display for DType {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        if *self == Float32 {
+            write!(f, "float32")
+        } else {
+            write!(f, "float64")
+        }
+    }
+}
+
 impl From<DType> for JsonValue {
     fn from(value: DType) -> Self {
         match value {