src/cpp-common/bt2c/vector.hpp

   1 /*
   2  * SPDX-FileCopyrightText: 2022 Simon Marchi <simon.marchi@efficios.com>
   3  *
   4  * SPDX-License-Identifier: MIT
   5  */
   6
   7 #ifndef SRC_CPP_COMMON_VECTOR_HPP
   8 #define SRC_CPP_COMMON_VECTOR_HPP
   9
  10 #include <vector>
  11
  12 #include "common/assert.h"
  13
  14 namespace bt2c {
  15
  16 /*
  17  * Moves the last entry of `vec` to the index `idx`, then removes the last entry.
  18  *
  19  * Meant to be a direct replacement for g_ptr_array_remove_index_fast(), but for
  20  * `std::vector`.
  21  */
  22 template <typename T, typename AllocatorT>
  23 void vectorFastRemove(std::vector<T, AllocatorT>& vec,
  24                       const typename std::vector<T, AllocatorT>::size_type idx)
  25 {
  26     BT_ASSERT_DBG(idx < vec.size());
  27
  28     if (idx < vec.size() - 1) {
  29         vec[idx] = std::move(vec.back());
  30     }
  31
  32     vec.pop_back();
  33 }
  34
  35 } /* namespace bt2c */
  36
  37 #endif /* SRC_CPP_COMMON_VECTOR_HPP */