include/o3tl/temporary.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 #ifndef INCLUDED_O3TL_TEMPORARY_HXX
  11 #define INCLUDED_O3TL_TEMPORARY_HXX
  12
  13 #include <sal/config.h>
  14
  15 namespace o3tl
  16 {
  17 // Cast an rvalue to an lvalue.  Can be useful if a function parameter is a pointer/reference to T,
  18 // and some call site doesn't need the value beyond the call itself (e.g., in a call like
  19 // std::modf(x, &o3tl::temporary(double())) to obtain the fractional part of x, ignoring the
  20 // integral part).
  21 template <typename T> constexpr T& temporary(T&& x) { return static_cast<T&>(x); }
  22 template <typename T> constexpr T& temporary(T&) = delete;
  23 }
  24
  25 #endif /* INCLUDED_O3TL_TEMPORARY_HXX */
  26
  27 /* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */