Add function to enlarge basic_vecvec::bucket

include/cista/containers/vecvec.h

@@ -3,6 +3,7 @@
 #include <cassert>
 #include <iterator>
 #include <type_traits>
+#include <vector>
 
 #include "cista/containers/vector.h"
 #include "cista/verify.h"
@@ -69,6 +70,18 @@ struct basic_vecvec {
  }
  }
 
+ void grow(std::size_t const n, value_type const fill = value_type{}) {
+ verify(n >= size(), "bucket::grow: new size < old size");
+ auto const growth = n - size();
+ auto const elements = std::vector(growth, fill);
+
+ map_->data_.insert(std::next(std::begin(map_->data_), bucket_end_idx()),
+ elements.begin(), elements.end());
+ for (auto i = i_ + 1; i != map_->bucket_starts_.size(); ++i) {
+ map_->bucket_starts_[i] += growth;
+ }
+ }
+
  value_type& operator[](std::size_t const i) {
  assert(is_inside_bucket(i));
  return map_->data_[to_idx(map_->bucket_starts_[i_] + i)];

test/vecvec_test.cc

@@ -1,6 +1,7 @@
 #include <array>
 #include <memory>
 #include <set>
+#include <stdexcept>
 
 #include "doctest.h"
 
@@ -77,6 +78,30 @@ TEST_CASE("vecvec bucket emplace_back test") {
  CHECK_EQ("testx", d[key{2}].view());
 }
 
+TEST_CASE("vecvec bucket grow test") {
+ using key = cista::strong<unsigned, struct x_>;
+ using data = cista::raw::vecvec<key, char>;
+ using std::literals::operator""sv;
+
+ data d;
+ d.emplace_back("hello");
+ d.emplace_back("world");
+
+ {
+ d[key{0}].grow(10);
+
+ CHECK_EQ("hello\0\0\0\0\0"sv, d[key{0}].view());
+ CHECK_EQ("world", d[key{1}].view());
+ }
+ {
+ d[key{0}].grow(13, ' ');
+
+ CHECK_EQ("hello\0\0\0\0\0 "sv, d[key{0}].view());
+ CHECK_EQ("world", d[key{1}].view());
+ }
+ { CHECK_THROWS_AS(d[key{0}].grow(5), std::runtime_error); }
+}
+
 TEST_CASE("vecvec resize test") {
  using key = cista::strong<unsigned, struct x_>;
  using data = cista::raw::vecvec<key, char>;