include/o3tl/sprintf.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  */
   9
  10 #pragma once
  11
  12 #include <sal/config.h>
  13
  14 #include <cassert>
  15 #include <cstddef>
  16 #include <cstdio>
  17 #include <utility>
  18
  19 #include <o3tl/safeint.hxx>
  20
  21 namespace o3tl
  22 {
  23 // A drop-in replacement for safe uses of std::sprintf where it is statically known that the
  24 // provided buffer is large enough.  Compared to a plain use of std::sprintf, using o3tl::sprintf
  25 // for one makes it explicit that the call is considered safe and for another avoids deprecation
  26 // warnings on platforms like the macOS 13 SDK that mark std::sprintf as deprecated.  Many simple
  27 // uses of std::sprintf across the code base can be replaced with alternative code using e.g.
  28 // OString::number.  This is for the remaining formatting-rich cases for which there is no easy
  29 // replacement yet in our C++17 baseline.  Ultimately, it should be removed again once alternatives
  30 // for those remaining cases, like C++20 std::format, are available.
  31 template <std::size_t N, typename... T>
  32 int sprintf(char (&s)[N], char const* format, T&&... arguments)
  33 {
  34     auto const n = std::snprintf(s, N, format, std::forward<T>(arguments)...);
  35     assert(n < 0 || o3tl::make_unsigned(n) < N);
  36     (void)n;
  37     return n;
  38 }
  39 }
  40
  41 /* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */