diff --git a/core/distributed/partition.cpp b/core/distributed/partition.cpp
index 575ca83aba6..22f0fdb3d94 100644
--- a/core/distributed/partition.cpp
+++ b/core/distributed/partition.cpp
@@ -123,7 +123,7 @@ void Partition<LocalIndexType, GlobalIndexType>::finalize_construction()
 
 
 template <typename LocalIndexType, typename GlobalIndexType>
-bool Partition<LocalIndexType, GlobalIndexType>::has_connected_parts()
+bool Partition<LocalIndexType, GlobalIndexType>::has_connected_parts() const
 {
     return this->get_num_parts() - this->get_num_empty_parts() ==
            this->get_num_ranges();
@@ -131,7 +131,7 @@ bool Partition<LocalIndexType, GlobalIndexType>::has_connected_parts()
 
 
 template <typename LocalIndexType, typename GlobalIndexType>
-bool Partition<LocalIndexType, GlobalIndexType>::has_ordered_parts()
+bool Partition<LocalIndexType, GlobalIndexType>::has_ordered_parts() const
 {
     if (this->has_connected_parts()) {
         auto exec = this->get_executor();
diff --git a/include/ginkgo/core/distributed/partition.hpp b/include/ginkgo/core/distributed/partition.hpp
index fa8b2739400..a40f30f7137 100644
--- a/include/ginkgo/core/distributed/partition.hpp
+++ b/include/ginkgo/core/distributed/partition.hpp
@@ -231,7 +231,7 @@ class Partition
      *
      * @return  true if each part has no more than one contiguous range.
      */
-    bool has_connected_parts();
+    bool has_connected_parts() const;
 
     /**
      * Checks if the ranges are ordered by their part index.
@@ -240,7 +240,7 @@ class Partition
      *
      * @return  true if the ranges are ordered by their part index.
      */
-    bool has_ordered_parts();
+    bool has_ordered_parts() const;
 
     /**
      * Builds a partition from a given mapping global_index -> part_id.
diff --git a/include/ginkgo/core/distributed/partition_helpers.hpp b/include/ginkgo/core/distributed/partition_helpers.hpp
index d9b2fee3d14..889347674c8 100644
--- a/include/ginkgo/core/distributed/partition_helpers.hpp
+++ b/include/ginkgo/core/distributed/partition_helpers.hpp
@@ -56,12 +56,14 @@ class Partition;
  * Builds a partition from a local range.
  *
  * @param exec  the Executor on which the partition should be built.
- * @param local_range the start and end indices of the local range.
  * @param comm  the communicator used to determine the global partition.
+ * @param local_range the start and end indices of the local range.
  *
- * @warning The local ranges have to be continuous and ascending. This means
- *          that for a process `i` with `range[i] = [s_i, e_i)` then for process
- *          `j = i+1` `range[j] = [s_j = e_i, e_j)`.
+ * @warning  This throws, if the resulting partition would contain gaps.
+ *           That means that for a partition of size `n` every local range `r_i
+ *           = [s_i, e_i)` either `s_i != 0` and another local range `r_j =
+ *           [s_j, e_j = s_i)` exists, or `e_i != n` and another local range
+ *           `r_j = [s_j = e_i, e_j)` exists.
  *
  * @return a Partition where each range has the individual local_start
  *         and local_ends.
@@ -76,8 +78,8 @@ build_partition_from_local_range(std::shared_ptr<const Executor> exec,
  * Builds a partition from a local size.
  *
  * @param exec  the Executor on which the partition should be built.
- * @param local_range the number of the locally owned indices
  * @param comm  the communicator used to determine the global partition.
+ * @param local_range the number of the locally owned indices
  *
  * @return a Partition where each range has the specified local size. More
  *         specifically, if this is called on process i with local_size `s_i`,
diff --git a/test/distributed/partition_helper_kernels.cpp b/test/distributed/partition_helper_kernels.cpp
index 441da3b8bd4..3cc472cd3b6 100644
--- a/test/distributed/partition_helper_kernels.cpp
+++ b/test/distributed/partition_helper_kernels.cpp
@@ -64,7 +64,7 @@ template <typename IndexType>
 std::vector<IndexType> create_iota(IndexType min, IndexType max)
 {
     std::vector<IndexType> iota(
-        clamp(max - min, static_cast<IndexType>(0), max));
+        clamp(max - min, IndexType(0), max));
     std::iota(iota.begin(), iota.end(), min);
     return iota;
 }
@@ -98,7 +98,7 @@ std::vector<std::size_t> sample_unique(std::size_t min, std::size_t max,
     std::default_random_engine engine;
     auto values = create_iota(min, max);
     std::shuffle(values.begin(), values.end(), engine);
-    values.erase(values.begin() + clamp(n, 0ul, values.size()), values.end());
+    values.erase(values.begin() + clamp(n, gko::size_type(0), values.size()), values.end());
     return values;
 }