Added a samples_view() method to the SampleHeaders class

This allows the names of samples stored in a SampleHeaders instance to be efficiently iterated via a view of the keys of an internal map.

Author: alancleary

libtiledbvcf/src/dataset/tiledbvcfdataset.cc

@@ -28,7 +28,6 @@
 #include <cstdint>
 #include <future>
 #include <map>
-#include <ranges>
 #include <string>
 #include <vector>
 
@@ -1355,11 +1354,11 @@ void TileDBVCFDataset::SampleHeaders::set_sample_header(
         Indexes& indexes = sample_index_lookup[sample_name];
         return indexes.header_idx == hdr_idx;
       };
-      auto samples_view = std::views::keys(sample_index_lookup);
+      auto samples = samples_view();
       std::vector<std::string> unique_hdr_samples;
       std::copy_if(
-          samples_view.begin(),
-          samples_view.end(),
+          samples.begin(),
+          samples.end(),
           std::back_inserter(unique_hdr_samples),
           unique_hdr_filter);
       std::string unqiue_hdr_samples_str = utils::join(unique_hdr_samples, ',');

libtiledbvcf/src/dataset/tiledbvcfdataset.h

@@ -29,6 +29,7 @@
 
 #include <map>
 #include <memory>
+#include <ranges>
 #include <string>
 #include <thread>
 #include <unordered_set>
@@ -281,6 +282,16 @@ class TileDBVCFDataset {
      */
     SafeBCFHdr get_sample_header(const std::string& sample) const;
 
+    /**
+     * Returns the sample names stored as a view of the internal lookup map.
+     *
+     * @param sample The name of the sample to get the header for
+     * @return The first header
+     */
+    auto samples_view() {
+      return std::views::keys(sample_index_lookup);
+    };
+
     /**
      * Gets sample names in the order their heaeders are returned by the
      * TileDB header array query.