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      1 /* Copyright (C) 2017-2024 Free Software Foundation, Inc.
      2 
      3    This file is part of GDB.
      4 
      5    This program is free software; you can redistribute it and/or modify
      6    it under the terms of the GNU General Public License as published by
      7    the Free Software Foundation; either version 3 of the License, or
      8    (at your option) any later version.
      9 
     10    This program is distributed in the hope that it will be useful,
     11    but WITHOUT ANY WARRANTY; without even the implied warranty of
     12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     13    GNU General Public License for more details.
     14 
     15    You should have received a copy of the GNU General Public License
     16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
     17 
     18 #ifndef COMMON_BYTE_VECTOR_H
     19 #define COMMON_BYTE_VECTOR_H
     20 
     21 #include "gdbsupport/def-vector.h"
     22 
     23 namespace gdb {
     24 
     25 /* byte_vector is a gdb_byte std::vector with a custom allocator that
     26    unlike std::vector<gdb_byte> does not zero-initialize new elements
     27    by default when the vector is created/resized.  This is what you
     28    usually want when working with byte buffers, since if you're
     29    creating or growing a buffer you'll most surely want to fill it in
     30    with data, in which case zero-initialization would be a
     31    pessimization.  For example:
     32 
     33      gdb::byte_vector buf (some_large_size);
     34      fill_with_data (buf.data (), buf.size ());
     35 
     36    On the odd case you do need zero initialization, then you can still
     37    call the overloads that specify an explicit value, like:
     38 
     39      gdb::byte_vector buf (some_initial_size, 0);
     40      buf.resize (a_bigger_size, 0);
     41 
     42    (Or use std::vector<gdb_byte> instead.)
     43 
     44    Note that unlike std::vector<gdb_byte>, function local
     45    gdb::byte_vector objects constructed with an initial size like:
     46 
     47      gdb::byte_vector buf (some_size);
     48      fill_with_data (buf.data (), buf.size ());
     49 
     50    usually compile down to the exact same as:
     51 
     52      std::unique_ptr<byte[]> buf (new gdb_byte[some_size]);
     53      fill_with_data (buf.get (), some_size);
     54 
     55    with the former having the advantage of being a bit more readable,
     56    and providing the whole std::vector API, if you end up needing it.
     57 */
     58 using byte_vector = gdb::def_vector<gdb_byte>;
     59 using char_vector = gdb::def_vector<char>;
     60 
     61 } /* namespace gdb */
     62 
     63 #endif /* COMMON_DEF_VECTOR_H */
     64