src/cpp-common/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 #include "common/assert.h"
  12
  13 namespace bt2_common {
  14
  15 /*
  16  * Moves the last entry of `vec` to the index `idx`, then removes the last entry.
  17  *
  18  * Meant to be a direct replacement for g_ptr_array_remove_index_fast(), but for
  19  * `std::vector`.
  20  */
  21 template <typename T, typename AllocatorT>
  22 void vectorFastRemove(std::vector<T, AllocatorT>& vec,
  23                       const typename std::vector<T, AllocatorT>::size_type idx)
  24 {
  25     BT_ASSERT_DBG(idx < vec.size());
  26
  27     if (idx < vec.size() - 1) {
  28         vec[idx] = std::move(vec.back());
  29     }
  30
  31     vec.pop_back();
  32 }
  33
  34 } /* namespace bt2_common */
  35
  36 #endif /* SRC_CPP_COMMON_VECTOR_HPP */