From 0a8943844f9a7b204d86e350e34a0453d126d2bf Mon Sep 17 00:00:00 2001 From: Wolfgang Bangerth Date: Sun, 22 Feb 2015 22:58:52 -0600 Subject: [PATCH] Add a workaround class for std::unique_ptr that can also be used in the non-C++11 context. --- doc/news/changes.h | 7 ++ include/deal.II/base/std_cxx11/unique_ptr.h | 83 +++++++++++++++++++ tests/base/unique_ptr_01.cc | 92 +++++++++++++++++++++ tests/base/unique_ptr_01.output | 2 + 4 files changed, 184 insertions(+) create mode 100644 include/deal.II/base/std_cxx11/unique_ptr.h create mode 100644 tests/base/unique_ptr_01.cc create mode 100644 tests/base/unique_ptr_01.output diff --git a/doc/news/changes.h b/doc/news/changes.h index dc72729f46..4b616855f0 100644 --- a/doc/news/changes.h +++ b/doc/news/changes.h @@ -350,6 +350,13 @@ inconvenience this causes.

Specific improvements

    +
  1. New: There is now a class std_cxx11::unique_ptr that provides + the functionality of std::unique_ptr in C++11 mode, and that + provides an emulation for older compilers. +
    + (Wolfgang Bangerth, 2015/02/22) +
    2. +
  2. New: IndexSet now has a local typedef IndexSet::value_type.
    (Wolfgang Bangerth, 2015/02/22) diff --git a/include/deal.II/base/std_cxx11/unique_ptr.h b/include/deal.II/base/std_cxx11/unique_ptr.h new file mode 100644 index 0000000000..9e4f931310 --- /dev/null +++ b/include/deal.II/base/std_cxx11/unique_ptr.h @@ -0,0 +1,83 @@ +// --------------------------------------------------------------------- +// +// Copyright (C) 2015 by the deal.II authors +// +// This file is part of the deal.II library. +// +// The deal.II library is free software; you can use it, redistribute +// it, and/or modify it under the terms of the GNU Lesser General +// Public License as published by the Free Software Foundation; either +// version 2.1 of the License, or (at your option) any later version. +// The full text of the license can be found in the file LICENSE at +// the top level of the deal.II distribution. +// +// --------------------------------------------------------------------- + +#ifndef __deal2__std_cxx11_unique_ptr_h +#define __deal2__std_cxx11_unique_ptr_h + + +#include + +#ifdef DEAL_II_WITH_CXX11 + +# include +DEAL_II_NAMESPACE_OPEN +namespace std_cxx11 +{ + using std::unique_ptr; +} +DEAL_II_NAMESPACE_CLOSE + +#else + +#include +DEAL_II_NAMESPACE_OPEN +namespace std_cxx11 +{ + /** + * Implementation of a basic replacement for C++11's std::unique_ptr + * class. + * + * BOOST does not have a replacement for std::unique_ptr (because + * unique_ptr requires move semantics that aren't available unless + * you have a C++11 compiler -- in which case you also have + * std::unique_ptr; see for example + * http://stackoverflow.com/questions/2953530/unique-ptr-boost-equivalent) + * + * Consequently, we emulate the class by just wrapping a + * boost::shared_ptr in the cheapest possible way -- by just + * deriving from it and repeating the basic constructors. Everything + * else is inherited from the shared_ptr class. + * + * This replacement comes with a certain overhead: doing reference + * counting instead of just passing ownership of pointers has a + * cost. But we don't use unique_ptrs in expensive places, and it is + * also a cost that will disappear once we require C++11 (and the + * cost of course does not apply if your compiler already supports + * C++11 and deal.II uses it). + */ + template + class unique_ptr : public boost::shared_ptr + { + public: + unique_ptr () {} + + template + explicit unique_ptr (Y *p) + : + boost::shared_ptr(p) + {} + }; + +} +DEAL_II_NAMESPACE_CLOSE + +#endif + +// then allow using the old namespace name instead of the new one +DEAL_II_NAMESPACE_OPEN +namespace std_cxx1x = std_cxx11; +DEAL_II_NAMESPACE_CLOSE + +#endif diff --git a/tests/base/unique_ptr_01.cc b/tests/base/unique_ptr_01.cc new file mode 100644 index 0000000000..b0d430ea10 --- /dev/null +++ b/tests/base/unique_ptr_01.cc @@ -0,0 +1,92 @@ +// --------------------------------------------------------------------- +// +// Copyright (C) 2015 by the deal.II authors +// +// This file is part of the deal.II library. +// +// The deal.II library is free software; you can use it, redistribute +// it, and/or modify it under the terms of the GNU Lesser General +// Public License as published by the Free Software Foundation; either +// version 2.1 of the License, or (at your option) any later version. +// The full text of the license can be found in the file LICENSE at +// the top level of the deal.II distribution. +// +// --------------------------------------------------------------------- + + + +#include "../tests.h" +#include +#include +#include + +// counter for how many objects of type X there are +int counter = 0; + +struct X +{ + X () + { + ++counter; + } + + X (const X &) + { + ++counter; + } + + ~X () + { + --counter; + } +}; + + + +int main () +{ + std::ofstream logfile("output"); + deallog.attach(logfile); + deallog.depth_console(0); + deallog.threshold_double(1.e-10); + + // test with plain new/delete + { + Assert (counter == 0, ExcInternalError()); + { + X *p = new X; + Assert (counter == 1, ExcInternalError()); + delete p; + } + Assert (counter == 0, ExcInternalError()); + } + + // test with plain unique_ptr + { + Assert (counter == 0, ExcInternalError()); + { + std_cxx11::unique_ptr p (new X); + Assert (counter == 1, ExcInternalError()); + } + Assert (counter == 0, ExcInternalError()); + } + + // test with plain unique_ptr, but also copy stuff. this only works + // with move constructors, so test only in C++11 mode +#ifdef DEAL_II_WITH_CXX11 + { + Assert (counter == 0, ExcInternalError()); + { + std_cxx11::unique_ptr p (new X); + Assert (counter == 1, ExcInternalError()); + + std_cxx11::unique_ptr q = std::move(p); + Assert (counter == 1, ExcInternalError()); + } + Assert (counter == 0, ExcInternalError()); + } +#endif + + deallog << "OK" << std::endl; +} + diff --git a/tests/base/unique_ptr_01.output b/tests/base/unique_ptr_01.output new file mode 100644 index 0000000000..0fd8fc12f0 --- /dev/null +++ b/tests/base/unique_ptr_01.output @@ -0,0 +1,2 @@ + +DEAL::OK -- 2.39.5