scikit-learn
diff --git a/‎doc/whats_new/v1.4.rst
+5 b/‎doc/whats_new/v1.4.rst
+5
diff --git a/‎sklearn/metrics/_dist_metrics.pxd.tp
+10-10 b/‎sklearn/metrics/_dist_metrics.pxd.tp
+10-10
@@ -216,6 +216,11 @@ Changelog
   for CSR × CSR,  Dense × CSR, and CSR × Dense datasets is now 1.5x faster.
   :pr:`26765` by :user:`Meekail Zain <micky774>`
 
+- |Efficiency| Computing distances via :class:`metrics.DistanceMetric`
+  for CSR × CSR, Dense × CSR, and CSR × Dense now uses ~50% less memory,
+  and outputs distances in the same dtype as the provided data.
+  :pr:`27006` by :user:`Meekail Zain <micky774>`
+
 :mod:`sklearn.utils`
 ....................
 
 
@@ -71,21 +71,21 @@ cdef class DistanceMetric{{name_suffix}}(DistanceMetric):
     cdef object func
     cdef object kwargs
 
-    cdef float64_t dist(
+    cdef {{INPUT_DTYPE_t}} dist(
         self,
         const {{INPUT_DTYPE_t}}* x1,
         const {{INPUT_DTYPE_t}}* x2,
         intp_t size,
     ) except -1 nogil
 
-    cdef float64_t rdist(
+    cdef {{INPUT_DTYPE_t}} rdist(
         self,
         const {{INPUT_DTYPE_t}}* x1,
         const {{INPUT_DTYPE_t}}* x2,
         intp_t size,
     ) except -1 nogil
 
-    cdef float64_t dist_csr(
+    cdef {{INPUT_DTYPE_t}} dist_csr(
         self,
         const {{INPUT_DTYPE_t}}* x1_data,
         const int32_t* x1_indices,
@@ -98,7 +98,7 @@ cdef class DistanceMetric{{name_suffix}}(DistanceMetric):
         const intp_t size,
     ) except -1 nogil
 
-    cdef float64_t rdist_csr(
+    cdef {{INPUT_DTYPE_t}} rdist_csr(
         self,
         const {{INPUT_DTYPE_t}}* x1_data,
         const int32_t* x1_indices,
@@ -114,14 +114,14 @@ cdef class DistanceMetric{{name_suffix}}(DistanceMetric):
     cdef int pdist(
         self,
         const {{INPUT_DTYPE_t}}[:, ::1] X,
-        float64_t[:, ::1] D,
+        {{INPUT_DTYPE_t}}[:, ::1] D,
     ) except -1
 
     cdef int cdist(
         self,
         const {{INPUT_DTYPE_t}}[:, ::1] X,
         const {{INPUT_DTYPE_t}}[:, ::1] Y,
-        float64_t[:, ::1] D,
+        {{INPUT_DTYPE_t}}[:, ::1] D,
     ) except -1
 
     cdef int pdist_csr(
@@ -130,7 +130,7 @@ cdef class DistanceMetric{{name_suffix}}(DistanceMetric):
         const int32_t[::1] x1_indices,
         const int32_t[::1] x1_indptr,
         const intp_t size,
-        float64_t[:, ::1] D,
+        {{INPUT_DTYPE_t}}[:, ::1] D,
     ) except -1 nogil
 
     cdef int cdist_csr(
@@ -142,11 +142,11 @@ cdef class DistanceMetric{{name_suffix}}(DistanceMetric):
         const int32_t[::1] x2_indices,
         const int32_t[::1] x2_indptr,
         const intp_t size,
-        float64_t[:, ::1] D,
+        {{INPUT_DTYPE_t}}[:, ::1] D,
     ) except -1 nogil
 
-    cdef float64_t _rdist_to_dist(self, {{INPUT_DTYPE_t}} rdist) except -1 nogil
+    cdef {{INPUT_DTYPE_t}} _rdist_to_dist(self, {{INPUT_DTYPE_t}} rdist) except -1 nogil
 
-    cdef float64_t _dist_to_rdist(self, {{INPUT_DTYPE_t}} dist) except -1 nogil
+    cdef {{INPUT_DTYPE_t}} _dist_to_rdist(self, {{INPUT_DTYPE_t}} dist) except -1 nogil
 
 {{endfor}}