Merge branch 'master' into compatibility

external/CMakeLists.txt

@@ -23,3 +23,4 @@
 #
 
 add_subdirectory(OpenGL)
+add_subdirectory(Optional)

external/Optional/CMakeLists.txt

@@ -0,0 +1,25 @@
+#
+#   This file is part of Magnum.
+#
+#   Copyright © 2010, 2011, 2012, 2013 Vladimír Vondruš <mosra@centrum.cz>
+#
+#   Permission is hereby granted, free of charge, to any person obtaining a
+#   copy of this software and associated documentation files (the "Software"),
+#   to deal in the Software without restriction, including without limitation
+#   the rights to use, copy, modify, merge, publish, distribute, sublicense,
+#   and/or sell copies of the Software, and to permit persons to whom the
+#   Software is furnished to do so, subject to the following conditions:
+#
+#   The above copyright notice and this permission notice shall be included
+#   in all copies or substantial portions of the Software.
+#
+#   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+#   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+#   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+#   THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+#   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+#   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+#   DEALINGS IN THE SOFTWARE.
+#
+
+install(FILES optional.hpp DESTINATION ${MAGNUM_INCLUDE_INSTALL_DIR}/Optional)

external/Optional/LICENSE_1_0.txt

@@ -0,0 +1,23 @@
+Boost Software License - Version 1.0 - August 17th, 2003
+
+Permission is hereby granted, free of charge, to any person or organization
+obtaining a copy of the software and accompanying documentation covered by
+this license (the "Software") to use, reproduce, display, distribute,
+execute, and transmit the Software, and to prepare derivative works of the
+Software, and to permit third-parties to whom the Software is furnished to
+do so, all subject to the following:
+
+The copyright notices in the Software and this entire statement, including
+the above license grant, this restriction and the following disclaimer,
+must be included in all copies of the Software, in whole or in part, and
+all derivative works of the Software, unless such copies or derivative
+works are solely in the form of machine-executable object code generated by
+a source language processor.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
+SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
+FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.

external/Optional/optional.hpp

@@ -0,0 +1,943 @@
+// Copyright (C) 2011 - 2012 Andrzej Krzemienski.
+//
+// Use, modification, and distribution is subject to the Boost Software
+// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+//
+// The idea and interface is based on Boost.Optional library
+// authored by Fernando Luis Cacciola Carballal
+
+# ifndef ___OPTIONAL_HPP___
+# define ___OPTIONAL_HPP___
+
+# include <utility>
+# include <type_traits>
+# include <initializer_list>
+# include <cassert>
+# include <functional>
+# include <string>
+# include <stdexcept>
+
+# define REQUIRES(...) typename enable_if<__VA_ARGS__::value, bool>::type = false
+
+# if defined __clang__
+#  define OPTIONAL_HAS_USING 1
+#  if (__clang_major__ > 2) || (__clang_major__ == 2) && (__clang_minor__ >= 9)
+#   define OPTIONAL_HAS_THIS_RVALUE_REFS 1
+#  else
+#   define OPTIONAL_HAS_THIS_RVALUE_REFS 0
+#  endif
+# elif defined __GNUC__
+#  if (__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 7))
+#   define OPTIONAL_HAS_USING 1
+#  else
+#   define OPTIONAL_HAS_USING 0
+#  endif
+#  if (__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ > 8 || ((__GNUC_MINOR__ == 8) && (__GNUC_PATCHLEVEL__ >= 1))))
+#   define OPTIONAL_HAS_THIS_RVALUE_REFS 1
+#  else
+#   define OPTIONAL_HAS_THIS_RVALUE_REFS 0
+#  endif
+# else
+#  define OPTIONAL_HAS_THIS_RVALUE_REFS 0
+#  define OPTIONAL_HAS_USING 0
+# endif
+
+
+namespace std{
+
+
+# if (defined __GNUC__) && ((__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 8)))
+    // leave it; our metafunctions are already defined.
+# elif (defined __clang__) && ((__clang_major__ > 3) || (__clang_major__ == 3) && (__clang_minor__ >= 3))
+    // leave it; our metafunctions are already defined.
+# else
+
+#  if OPTIONAL_HAS_USING
+// the only bit GCC 4.7 and clang 3.2 don't have
+template <class T>
+using is_trivially_destructible = typename std::has_trivial_destructor<T>;
+#  endif
+
+#  if (defined __GNUC__) && ((__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 7)))
+    // leave it; remaining metafunctions are already defined.
+#  elif defined __clang__
+    // leave it; remaining metafunctions are already defined.
+#  else
+
+
+// workaround for missing traits in GCC and CLANG
+template <class T>
+struct is_nothrow_move_constructible
+{
+  constexpr static bool value = std::is_nothrow_constructible<T, T&&>::value;
+};
+
+
+template <class T, class U>
+struct is_assignable
+{
+  template <class X, class Y>
+  static constexpr bool has_assign(...) { return false; }
+
+  template <class X, class Y, size_t S = sizeof(std::declval<X>() = std::declval<Y>()) >
+  static constexpr bool has_assign(bool) { return true; }
+
+  constexpr static bool value = has_assign<T, U>(true);
+};
+
+
+template <class T>
+struct is_nothrow_move_assignable
+{
+  template <class X, bool has_any_move_massign>
+  struct has_nothrow_move_assign {
+    constexpr static bool value = false;
+  };
+
+  template <class X>
+  struct has_nothrow_move_assign<X, true> {
+    constexpr static bool value = noexcept( std::declval<X&>() = std::declval<X&&>() );
+  };
+
+  constexpr static bool value = has_nothrow_move_assign<T, is_assignable<T&, T&&>::value>::value;
+};
+// end workaround
+
+
+#  endif // not as good as GCC 4.7
+# endif // not as good as GCC 4.8
+
+
+
+// 20.5.4, optional for object types
+template <class T> class optional;
+
+// 20.5.5, optional for lvalue reference types
+template <class T> class optional<T&>;
+
+
+// workaround: std utility functions aren't constexpr yet
+template <class T> inline constexpr T&& constexpr_forward(typename std::remove_reference<T>::type& t) noexcept
+{
+  return static_cast<T&&>(t);
+}
+
+template <class T> inline constexpr T&& constexpr_forward(typename std::remove_reference<T>::type&& t) noexcept
+{
+    static_assert(!std::is_lvalue_reference<T>::value, "!!");
+    return static_cast<T&&>(t);
+}
+
+template <class T> inline constexpr typename std::remove_reference<T>::type&& constexpr_move(T&& t) noexcept
+{
+    return static_cast<typename std::remove_reference<T>::type&&>(t);
+}
+
+
+#if defined NDEBUG
+# define ASSERTED_EXPRESSION(CHECK, EXPR) (EXPR)
+#else
+# define ASSERTED_EXPRESSION(CHECK, EXPR) ((CHECK) ? (EXPR) : (fail(#CHECK, __FILE__, __LINE__), (EXPR)))
+  inline void fail(const char* expr, const char* file, unsigned line)
+  {
+  # if defined __clang__ || defined __GNU_LIBRARY__
+    __assert(expr, file, line);
+  # elif defined __GNUC__
+    _assert(expr, file, line);
+  # else
+  #   error UNSUPPORTED COMPILER
+  # endif
+  }
+#endif
+
+
+template <typename T>
+struct has_overloaded_addressof
+{
+  template <class X>
+  static constexpr bool has_overload(...) { return false; }
+
+  template <class X, size_t S = sizeof(std::declval< X&>().operator&()) >
+  static constexpr bool has_overload(bool) { return true; }
+
+  constexpr static bool value = has_overload<T>(true);
+};
+
+
+
+template <typename T, REQUIRES(!has_overloaded_addressof<T>)>
+constexpr T* static_addressof(T& ref)
+{
+  return &ref;
+}
+
+template <typename T, REQUIRES(has_overloaded_addressof<T>)>
+T* static_addressof(T& ref)
+{
+  return std::addressof(ref);
+}
+
+
+
+template <class U>
+struct is_not_optional
+{
+  constexpr static bool value = true;
+};
+
+template <class T>
+struct is_not_optional<optional<T>>
+{
+  constexpr static bool value = false;
+};
+
+
+constexpr struct trivial_init_t{} trivial_init{};
+
+
+// 20.5.6, In-place construction
+constexpr struct in_place_t{} in_place{};
+
+
+// 20.5.7, Disengaged state indicator
+struct nullopt_t
+{
+  struct init{};
+  constexpr nullopt_t(init){};
+};
+constexpr nullopt_t nullopt{nullopt_t::init{}};
+
+
+// 20.5.8, class bad_optional_access
+class bad_optional_access : public logic_error {
+public:
+  explicit bad_optional_access(const string& what_arg) : logic_error{what_arg} {}
+  explicit bad_optional_access(const char* what_arg) : logic_error{what_arg} {}
+};
+
+
+template <class T>
+union storage_t
+{
+  unsigned char dummy_;
+  T value_;
+
+  constexpr storage_t( trivial_init_t ) noexcept : dummy_() {};
+
+  template <class... Args>
+  constexpr storage_t( Args&&... args ) : value_(constexpr_forward<Args>(args)...) {}
+
+  ~storage_t(){}
+};
+
+
+template <class T>
+union constexpr_storage_t
+{
+    unsigned char dummy_;
+    T value_;
+
+    constexpr constexpr_storage_t( trivial_init_t ) noexcept : dummy_() {};
+
+    template <class... Args>
+    constexpr constexpr_storage_t( Args&&... args ) : value_(constexpr_forward<Args>(args)...) {}
+
+    ~constexpr_storage_t() = default;
+};
+
+
+constexpr struct only_set_initialized_t{} only_set_initialized{};
+
+
+template <class T>
+struct optional_base
+{
+    bool init_;
+    storage_t<T> storage_;
+
+    constexpr optional_base() noexcept : init_(false), storage_(trivial_init) {};
+
+    constexpr explicit optional_base(only_set_initialized_t, bool init) noexcept : init_(init), storage_(trivial_init) {};
+
+    explicit constexpr optional_base(const T& v) : init_(true), storage_(v) {}
+
+    explicit constexpr optional_base(T&& v) : init_(true), storage_(constexpr_move(v)) {}
+
+    template <class... Args> explicit optional_base(in_place_t, Args&&... args)
+        : init_(true), storage_(constexpr_forward<Args>(args)...) {}
+
+    template <class U, class... Args, REQUIRES(is_constructible<T, std::initializer_list<U>>)>
+    explicit optional_base(in_place_t, std::initializer_list<U> il, Args&&... args)
+        : init_(true), storage_(il, std::forward<Args>(args)...) {}
+
+    ~optional_base() { if (init_) storage_.value_.T::~T(); }
+};
+
+
+template <class T>
+struct constexpr_optional_base
+{
+    bool init_;
+    constexpr_storage_t<T> storage_;
+
+    constexpr constexpr_optional_base() noexcept : init_(false), storage_(trivial_init) {};
+
+    constexpr explicit constexpr_optional_base(only_set_initialized_t, bool init) noexcept : init_(init), storage_(trivial_init) {};
+
+    explicit constexpr constexpr_optional_base(const T& v) : init_(true), storage_(v) {}
+
+    explicit constexpr constexpr_optional_base(T&& v) : init_(true), storage_(constexpr_move(v)) {}
+
+    template <class... Args> explicit constexpr constexpr_optional_base(in_place_t, Args&&... args)
+      : init_(true), storage_(constexpr_forward<Args>(args)...) {}
+
+    template <class U, class... Args, REQUIRES(is_constructible<T, std::initializer_list<U>>)>
+    explicit constexpr_optional_base(in_place_t, std::initializer_list<U> il, Args&&... args)
+      : init_(true), storage_(il, std::forward<Args>(args)...) {}
+
+    ~constexpr_optional_base() = default;
+};
+
+# if OPTIONAL_HAS_USING
+template <class T>
+using OptionalBase = typename std::conditional<
+    std::is_trivially_destructible<T>::value,
+    constexpr_optional_base<T>,
+    optional_base<T>
+>::type;
+# else
+#  define OptionalBase optional_base
+# endif
+
+template <class T>
+class optional : private OptionalBase<T>
+{
+  static_assert( !std::is_same<typename std::decay<T>::type, nullopt_t>::value, "bad T" );
+  static_assert( !std::is_same<typename std::decay<T>::type, in_place_t>::value, "bad T" );
+
+
+  constexpr bool initialized() const noexcept { return OptionalBase<T>::init_; }
+  T* dataptr() {  return std::addressof(OptionalBase<T>::storage_.value_); }
+  constexpr const T* dataptr() const { return static_addressof(OptionalBase<T>::storage_.value_); }
+
+# if OPTIONAL_HAS_THIS_RVALUE_REFS == 1
+  constexpr const T& contained_val() const& { return OptionalBase<T>::storage_.value_; }
+  T& contained_val() & { return OptionalBase<T>::storage_.value_; }
+  T&& contained_val() && { return std::move(OptionalBase<T>::storage_.value_); }
+# else
+  constexpr const T& contained_val() const { return OptionalBase<T>::storage_.value_; }
+  T& contained_val() { return OptionalBase<T>::storage_.value_; }
+# endif
+
+  void clear() noexcept {
+    if (initialized()) dataptr()->T::~T();
+    OptionalBase<T>::init_ = false;
+  }
+
+  template <class... Args>
+  void initialize(Args&&... args) noexcept(noexcept(T(std::forward<Args>(args)...)))
+  {
+    assert(!OptionalBase<T>::init_);
+    new (dataptr()) T(std::forward<Args>(args)...);
+    OptionalBase<T>::init_ = true;
+  }
+
+  template <class U, class... Args>
+  void initialize(std::initializer_list<U> il, Args&&... args) noexcept(noexcept(T(il, std::forward<Args>(args)...)))
+  {
+    assert(!OptionalBase<T>::init_);
+    new (dataptr()) T(il, std::forward<Args>(args)...);
+    OptionalBase<T>::init_ = true;
+  }
+
+public:
+  typedef T value_type;
+
+  // 20.5.5.1, constructors
+  constexpr optional() noexcept : OptionalBase<T>()  {};
+  constexpr optional(nullopt_t) noexcept : OptionalBase<T>() {};
+
+  optional(const optional& rhs)
+  : OptionalBase<T>(only_set_initialized, rhs.initialized())
+  {
+    if (rhs.initialized()) new (dataptr()) T(*rhs);
+  }
+
+  optional(optional&& rhs) noexcept(std::is_nothrow_move_constructible<T>::value)
+  : OptionalBase<T>(only_set_initialized, rhs.initialized())
+  {
+    if (rhs.initialized()) new (dataptr()) T(std::move(*rhs));
+  }
+
+  constexpr optional(const T& v) : OptionalBase<T>(v) {}
+
+  constexpr optional(T&& v) : OptionalBase<T>(constexpr_move(v)) {}
+
+  template <class... Args>
+    constexpr explicit optional(in_place_t, Args&&... args)
+        : OptionalBase<T>(in_place_t{}, constexpr_forward<Args>(args)...) {}
+
+    template <class U, class... Args, REQUIRES(is_constructible<T, std::initializer_list<U>>)>
+    explicit optional(in_place_t, std::initializer_list<U> il, Args&&... args)
+        : OptionalBase<T>(in_place_t{}, il, constexpr_forward<Args>(args)...) {}
+
+  // 20.5.4.2 Destructor
+  ~optional() = default;
+
+  // 20.5.4.3, assignment
+  optional& operator=(nullopt_t) noexcept
+  {
+    clear();
+    return *this;
+  }
+
+  optional& operator=(const optional& rhs)
+  {
+    if      (initialized() == true  && rhs.initialized() == false) clear();
+    else if (initialized() == false && rhs.initialized() == true)  initialize(*rhs);
+    else if (initialized() == true  && rhs.initialized() == true)  contained_val() = *rhs;
+    return *this;
+  }
+
+  optional& operator=(optional&& rhs)
+  noexcept(std::is_nothrow_move_assignable<T>::value && std::is_nothrow_move_constructible<T>::value)
+  {
+    if      (initialized() == true  && rhs.initialized() == false) clear();
+    else if (initialized() == false && rhs.initialized() == true)  initialize(std::move(*rhs));
+    else if (initialized() == true  && rhs.initialized() == true)  contained_val() = std::move(*rhs);
+    return *this;
+  }
+
+  template <class U>
+  auto operator=(U&& v)
+  -> typename enable_if
+  <
+    is_same<typename remove_reference<U>::type, T>::value,
+    optional&
+  >::type
+  {
+    if (initialized()) { contained_val() = std::forward<U>(v); }
+    else               { initialize(std::forward<U>(v));  }
+    return *this;
+  }
+
+
+  template <class... Args>
+  void emplace(Args&&... args)
+  {
+    clear();
+    initialize(std::forward<Args>(args)...);
+  }
+
+  template <class U, class... Args>
+  void emplace(initializer_list<U> il, Args&&... args)
+  {
+    clear();
+    initialize<U, Args...>(il, std::forward<Args>(args)...);
+  }
+
+  // 20.5.4.4 Swap
+  void swap(optional<T>& rhs) noexcept(is_nothrow_move_constructible<T>::value && noexcept(swap(declval<T&>(), declval<T&>())))
+  {
+    if      (initialized() == true  && rhs.initialized() == false) { rhs.initialize(std::move(**this)); clear(); }
+    else if (initialized() == false && rhs.initialized() == true)  { initialize(std::move(*rhs)); rhs.clear(); }
+    else if (initialized() == true  && rhs.initialized() == true)  { using std::swap; swap(**this, *rhs); }
+  }
+
+  // 20.5.4.5 Observers
+  constexpr T const* operator ->() const {
+    return ASSERTED_EXPRESSION(initialized(), dataptr());
+  }
+
+  T* operator ->() {
+    assert (initialized());
+    return dataptr();
+  }
+
+  constexpr T const& operator *() const {
+    return ASSERTED_EXPRESSION(initialized(), contained_val());
+  }
+
+  T& operator *() {
+    assert (initialized());
+    return contained_val();
+  }
+
+  constexpr T const& value() const {
+    return initialized() ? contained_val() : (throw bad_optional_access("bad optional access"), contained_val());
+  }
+
+  T& value() {
+    return initialized() ? contained_val() : (throw bad_optional_access("bad optional access"), contained_val());
+  }
+
+  constexpr explicit operator bool() const noexcept { return initialized(); }
+
+# if OPTIONAL_HAS_THIS_RVALUE_REFS == 1
+
+  template <class V>
+  constexpr T value_or(V&& v) const&
+  {
+    return *this ? **this : static_cast<T>(constexpr_forward<V>(v));
+  }
+
+  template <class V>
+  T value_or(V&& v) &&
+  {
+    return *this ? std::move(const_cast<optional<T>&>(*this).contained_val()) : static_cast<T>(constexpr_forward<V>(v));
+  }
+
+# else
+
+  template <class V>
+  constexpr T value_or(V&& v) const
+  {
+    return *this ? **this : static_cast<T>(constexpr_forward<V>(v));
+  }
+
+# endif
+
+};
+
+
+template <class T>
+class optional<T&>
+{
+  static_assert( !std::is_same<T, nullopt_t>::value, "bad T" );
+  static_assert( !std::is_same<T, in_place_t>::value, "bad T" );
+  T* ref;
+
+public:
+
+  // 20.5.5.1, construction/destruction
+  constexpr optional() noexcept : ref(nullptr) {}
+
+  constexpr optional(nullopt_t) noexcept : ref(nullptr) {}
+
+  constexpr optional(T& v) noexcept : ref(static_addressof(v)) {}
+
+  optional(T&&) = delete;
+
+  constexpr optional(const optional& rhs) noexcept : ref(rhs.ref) {}
+
+  explicit constexpr optional(in_place_t, T& v) noexcept : ref(static_addressof(v)) {}
+
+  explicit optional(in_place_t, T&&) = delete;
+
+  ~optional() = default;
+
+  // 20.5.5.2, mutation
+  optional& operator=(nullopt_t) noexcept {
+    ref = nullptr;
+    return *this;
+  }
+
+  // optional& operator=(const optional& rhs) noexcept {
+    // ref = rhs.ref;
+    // return *this;
+  // }
+
+  // optional& operator=(optional&& rhs) noexcept {
+    // ref = rhs.ref;
+    // return *this;
+  // }
+
+  template <typename U>
+  auto operator=(U&& rhs) noexcept
+  -> typename enable_if
+  <
+    is_same<typename decay<U>::type, optional<T&>>::value,
+    optional&
+  >::type
+  {
+    ref = rhs.ref;
+    return *this;
+  }
+
+  template <typename U>
+  auto operator=(U&& rhs) noexcept
+  -> typename enable_if
+  <
+    !is_same<typename decay<U>::type, optional<T&>>::value,
+    optional&
+  >::type
+  = delete;
+
+  void emplace(T& v) noexcept {
+    ref = static_addressof(v);
+  }
+
+  void emplace(T&&) = delete;
+
+
+  void swap(optional<T&>& rhs) noexcept
+  {
+    std::swap(ref, rhs.ref);
+  }
+
+  // 20.5.5.3, observers
+  constexpr T* operator->() const {
+    return ASSERTED_EXPRESSION(ref, ref);
+  }
+
+  constexpr T& operator*() const {
+    return ASSERTED_EXPRESSION(ref, *ref);
+  }
+
+  constexpr T& value() const {
+    return ref ? *ref : (throw bad_optional_access("bad optional access"), *ref);
+  }
+
+  explicit constexpr operator bool() const noexcept {
+    return ref != nullptr;
+  }
+
+  template <class V>
+  constexpr typename decay<T>::type value_or(V&& v) const
+  {
+    return *this ? **this : static_cast<typename decay<T>::type>(constexpr_forward<V>(v));
+  }
+};
+
+
+template <class T>
+class optional<T&&>
+{
+  static_assert( sizeof(T) == 0, "optional rvalue referencs disallowed" );
+};
+
+
+// 20.5.8, Relational operators
+template <class T> constexpr bool operator==(const optional<T>& x, const optional<T>& y)
+{
+  return bool(x) != bool(y) ? false : bool(x) == false ? true : *x == *y;
+}
+
+template <class T> constexpr bool operator!=(const optional<T>& x, const optional<T>& y)
+{
+  return !(x == y);
+}
+
+template <class T> constexpr bool operator<(const optional<T>& x, const optional<T>& y)
+{
+  return (!y) ? false : (!x) ? true : *x < *y;
+}
+
+template <class T> constexpr bool operator>(const optional<T>& x, const optional<T>& y)
+{
+  return (y < x);
+}
+
+template <class T> constexpr bool operator<=(const optional<T>& x, const optional<T>& y)
+{
+  return !(y < x);
+}
+
+template <class T> constexpr bool operator>=(const optional<T>& x, const optional<T>& y)
+{
+  return !(x < y);
+}
+
+
+// 20.5.9 Comparison with nullopt
+template <class T> constexpr bool operator==(const optional<T>& x, nullopt_t) noexcept
+{
+  return (!x);
+}
+
+template <class T> constexpr bool operator==(nullopt_t, const optional<T>& x) noexcept
+{
+  return (!x);
+}
+
+template <class T> constexpr bool operator!=(const optional<T>& x, nullopt_t) noexcept
+{
+  return bool(x);
+}
+
+template <class T> constexpr bool operator!=(nullopt_t, const optional<T>& x) noexcept
+{
+  return bool(x);
+}
+
+template <class T> constexpr bool operator<(const optional<T>&, nullopt_t) noexcept
+{
+  return false;
+}
+
+template <class T> constexpr bool operator<(nullopt_t, const optional<T>& x) noexcept
+{
+  return bool(x);
+}
+
+template <class T> constexpr bool operator<=(const optional<T>& x, nullopt_t) noexcept
+{
+  return (!x);
+}
+
+template <class T> constexpr bool operator<=(nullopt_t, const optional<T>&) noexcept
+{
+  return true;
+}
+
+template <class T> constexpr bool operator>(const optional<T>& x, nullopt_t) noexcept
+{
+  return bool(x);
+}
+
+template <class T> constexpr bool operator>(nullopt_t, const optional<T>&) noexcept
+{
+  return false;
+}
+
+template <class T> constexpr bool operator>=(const optional<T>&, nullopt_t) noexcept
+{
+  return true;
+}
+
+template <class T> constexpr bool operator>=(nullopt_t, const optional<T>& x) noexcept
+{
+  return (!x);
+}
+
+
+
+// 20.5.10, Comparison with T
+template <class T> constexpr bool operator==(const optional<T>& x, const T& v)
+{
+  return bool(x) ? *x == v : false;
+}
+
+template <class T> constexpr bool operator==(const T& v, const optional<T>& x)
+{
+  return bool(x) ? v == *x : false;
+}
+
+template <class T> constexpr bool operator!=(const optional<T>& x, const T& v)
+{
+  return bool(x) ? *x != v : true;
+}
+
+template <class T> constexpr bool operator!=(const T& v, const optional<T>& x)
+{
+  return bool(x) ? v != *x : true;
+}
+
+template <class T> constexpr bool operator<(const optional<T>& x, const T& v)
+{
+  return bool(x) ? *x < v : true;
+}
+
+template <class T> constexpr bool operator>(const T& v, const optional<T>& x)
+{
+  return bool(x) ? v > *x : true;
+}
+
+template <class T> constexpr bool operator>(const optional<T>& x, const T& v)
+{
+  return bool(x) ? *x > v : false;
+}
+
+template <class T> constexpr bool operator<(const T& v, const optional<T>& x)
+{
+  return bool(x) ? v < *x : false;
+}
+
+template <class T> constexpr bool operator>=(const optional<T>& x, const T& v)
+{
+  return bool(x) ? *x >= v : false;
+}
+
+template <class T> constexpr bool operator<=(const T& v, const optional<T>& x)
+{
+  return bool(x) ? v <= *x : false;
+}
+
+template <class T> constexpr bool operator<=(const optional<T>& x, const T& v)
+{
+  return bool(x) ? *x <= v : true;
+}
+
+template <class T> constexpr bool operator>=(const T& v, const optional<T>& x)
+{
+  return bool(x) ? v >= *x : true;
+}
+
+
+// Comparison of optionsl<T&> with T
+template <class T> constexpr bool operator==(const optional<T&>& x, const T& v)
+{
+  return bool(x) ? *x == v : false;
+}
+
+template <class T> constexpr bool operator==(const T& v, const optional<T&>& x)
+{
+  return bool(x) ? v == *x : false;
+}
+
+template <class T> constexpr bool operator!=(const optional<T&>& x, const T& v)
+{
+  return bool(x) ? *x != v : true;
+}
+
+template <class T> constexpr bool operator!=(const T& v, const optional<T&>& x)
+{
+  return bool(x) ? v != *x : true;
+}
+
+template <class T> constexpr bool operator<(const optional<T&>& x, const T& v)
+{
+  return bool(x) ? *x < v : true;
+}
+
+template <class T> constexpr bool operator>(const T& v, const optional<T&>& x)
+{
+  return bool(x) ? v > *x : true;
+}
+
+template <class T> constexpr bool operator>(const optional<T&>& x, const T& v)
+{
+  return bool(x) ? *x > v : false;
+}
+
+template <class T> constexpr bool operator<(const T& v, const optional<T&>& x)
+{
+  return bool(x) ? v < *x : false;
+}
+
+template <class T> constexpr bool operator>=(const optional<T&>& x, const T& v)
+{
+  return bool(x) ? *x >= v : false;
+}
+
+template <class T> constexpr bool operator<=(const T& v, const optional<T&>& x)
+{
+  return bool(x) ? v <= *x : false;
+}
+
+template <class T> constexpr bool operator<=(const optional<T&>& x, const T& v)
+{
+  return bool(x) ? *x <= v : true;
+}
+
+template <class T> constexpr bool operator>=(const T& v, const optional<T&>& x)
+{
+  return bool(x) ? v >= *x : true;
+}
+
+// Comparison of optionsl<T const&> with T
+template <class T> constexpr bool operator==(const optional<const T&>& x, const T& v)
+{
+  return bool(x) ? *x == v : false;
+}
+
+template <class T> constexpr bool operator==(const T& v, const optional<const T&>& x)
+{
+  return bool(x) ? v == *x : false;
+}
+
+template <class T> constexpr bool operator!=(const optional<const T&>& x, const T& v)
+{
+  return bool(x) ? *x != v : true;
+}
+
+template <class T> constexpr bool operator!=(const T& v, const optional<const T&>& x)
+{
+  return bool(x) ? v != *x : true;
+}
+
+template <class T> constexpr bool operator<(const optional<const T&>& x, const T& v)
+{
+  return bool(x) ? *x < v : true;
+}
+
+template <class T> constexpr bool operator>(const T& v, const optional<const T&>& x)
+{
+  return bool(x) ? v > *x : true;
+}
+
+template <class T> constexpr bool operator>(const optional<const T&>& x, const T& v)
+{
+  return bool(x) ? *x > v : false;
+}
+
+template <class T> constexpr bool operator<(const T& v, const optional<const T&>& x)
+{
+  return bool(x) ? v < *x : false;
+}
+
+template <class T> constexpr bool operator>=(const optional<const T&>& x, const T& v)
+{
+  return bool(x) ? *x >= v : false;
+}
+
+template <class T> constexpr bool operator<=(const T& v, const optional<const T&>& x)
+{
+  return bool(x) ? v <= *x : false;
+}
+
+template <class T> constexpr bool operator<=(const optional<const T&>& x, const T& v)
+{
+  return bool(x) ? *x <= v : true;
+}
+
+template <class T> constexpr bool operator>=(const T& v, const optional<const T&>& x)
+{
+  return bool(x) ? v >= *x : true;
+}
+
+
+// 20.5.12 Specialized algorithms
+template <class T>
+void swap(optional<T>& x, optional<T>& y) noexcept(noexcept(x.swap(y)))
+{
+  x.swap(y);
+}
+
+
+template <class T>
+constexpr optional<typename decay<T>::type> make_optional(T&& v)
+{
+  return optional<typename decay<T>::type>(constexpr_forward<T>(v));
+}
+
+template <class X>
+constexpr optional<X&> make_optional(reference_wrapper<X> v)
+{
+  return optional<X&>(v.get());
+}
+
+
+} // namespace std
+
+namespace std
+{
+  template <typename T>
+  struct hash<std::optional<T>>
+  {
+    typedef typename hash<T>::result_type result_type;
+    typedef std::optional<T> argument_type;
+
+    constexpr result_type operator()(argument_type const& arg) const {
+      return arg ? std::hash<T>{}(*arg) : result_type{};
+    }
+  };
+
+  template <typename T>
+  struct hash<std::optional<T&>>
+  {
+    typedef typename hash<T>::result_type result_type;
+    typedef std::optional<T&> argument_type;
+
+    constexpr result_type operator()(argument_type const& arg) const {
+      return arg ? std::hash<T>{}(*arg) : result_type{};
+    }
+  };
+}
+
+#ifdef OptionalBase
+# undef OptionalBase
+#endif
+
+# endif //___OPTIONAL_HPP___

src/TextureTools/distance-field.cpp

@@ -83,7 +83,7 @@ int DistanceFieldConverter::exec() {
     CORRADE_INTERNAL_ASSERT(importer && converter);
 
     /* Open input file */
-    Trade::ImageData2D* image = nullptr;
+    std::optional<Trade::ImageData2D> image;
     if(!importer->openFile(args.value("input")) || !(image = importer->image2D(0))) {
         Error() << "Cannot open file" << args.value("input");
         delete importer;
@@ -114,7 +114,6 @@ int DistanceFieldConverter::exec() {
     /* Do it */
     Debug() << "Converting image of size" << image->size() << "to distance field...";
     TextureTools::distanceField(input, output, {{}, args.value<Vector2i>("output-size")}, args.value<Int>("radius"), image->size());
-    delete image;
 
     /* Save image */
     Image2D result(ImageFormat::Red, ImageType::UnsignedByte);

src/Trade/AbstractImporter.cpp

@@ -28,6 +28,17 @@
 #include <Containers/Array.h>
 #include <Utility/Assert.h>
 
+#include "Trade/AbstractMaterialData.h"
+#include "Trade/CameraData.h"
+#include "Trade/ImageData.h"
+#include "Trade/LightData.h"
+#include "Trade/MeshData2D.h"
+#include "Trade/MeshData3D.h"
+#include "Trade/ObjectData2D.h"
+#include "Trade/ObjectData3D.h"
+#include "Trade/SceneData.h"
+#include "Trade/TextureData.h"
+
 namespace Magnum { namespace Trade {
 
 AbstractImporter::AbstractImporter() = default;
@@ -111,13 +122,13 @@ std::string AbstractImporter::sceneName(const UnsignedInt id) {
 
 std::string AbstractImporter::doSceneName(UnsignedInt) { return {}; }
 
-SceneData* AbstractImporter::scene(const UnsignedInt id) {
+std::optional<SceneData> AbstractImporter::scene(const UnsignedInt id) {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::scene(): no file opened", {});
     CORRADE_ASSERT(id < doSceneCount(), "Trade::AbstractImporter::scene(): index out of range", {});
     return doScene(id);
 }
 
-SceneData* AbstractImporter::doScene(UnsignedInt) { return nullptr; }
+std::optional<SceneData> AbstractImporter::doScene(UnsignedInt) { return std::nullopt; }
 
 UnsignedInt AbstractImporter::lightCount() const {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::lightCount(): no file opened", {});
@@ -141,13 +152,13 @@ std::string AbstractImporter::lightName(const UnsignedInt id) {
 
 std::string AbstractImporter::doLightName(UnsignedInt) { return {}; }
 
-LightData* AbstractImporter::light(const UnsignedInt id) {
+std::optional<LightData> AbstractImporter::light(const UnsignedInt id) {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::light(): no file opened", {});
     CORRADE_ASSERT(id < doLightCount(), "Trade::AbstractImporter::light(): index out of range", {});
     return doLight(id);
 }
 
-LightData* AbstractImporter::doLight(UnsignedInt) { return nullptr; }
+std::optional<LightData> AbstractImporter::doLight(UnsignedInt) { return std::nullopt; }
 
 UnsignedInt AbstractImporter::cameraCount() const {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::cameraCount(): no file opened", {});
@@ -171,13 +182,13 @@ std::string AbstractImporter::cameraName(const UnsignedInt id) {
 
 std::string AbstractImporter::doCameraName(UnsignedInt) { return {}; }
 
-CameraData* AbstractImporter::camera(const UnsignedInt id) {
+std::optional<CameraData> AbstractImporter::camera(const UnsignedInt id) {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::camera(): no file opened", {});
     CORRADE_ASSERT(id < doCameraCount(), "Trade::AbstractImporter::camera(): index out of range", {});
     return doCamera(id);
 }
 
-CameraData* AbstractImporter::doCamera(UnsignedInt) { return nullptr; }
+std::optional<CameraData> AbstractImporter::doCamera(UnsignedInt) { return std::nullopt; }
 
 UnsignedInt AbstractImporter::object2DCount() const {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::object2DCount(): no file opened", {});
@@ -201,13 +212,13 @@ std::string AbstractImporter::object2DName(const UnsignedInt id) {
 
 std::string AbstractImporter::doObject2DName(UnsignedInt) { return {}; }
 
-ObjectData2D* AbstractImporter::object2D(const UnsignedInt id) {
+std::unique_ptr<ObjectData2D> AbstractImporter::object2D(const UnsignedInt id) {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::object2D(): no file opened", {});
     CORRADE_ASSERT(id < doObject2DCount(), "Trade::AbstractImporter::object2D(): index out of range", {});
     return doObject2D(id);
 }
 
-ObjectData2D* AbstractImporter::doObject2D(UnsignedInt) { return nullptr; }
+std::unique_ptr<ObjectData2D> AbstractImporter::doObject2D(UnsignedInt) { return nullptr; }
 
 UnsignedInt AbstractImporter::object3DCount() const {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::object3DCount(): no file opened", {});
@@ -231,13 +242,13 @@ std::string AbstractImporter::object3DName(const UnsignedInt id) {
 
 std::string AbstractImporter::doObject3DName(UnsignedInt) { return {}; }
 
-ObjectData3D* AbstractImporter::object3D(const UnsignedInt id) {
+std::unique_ptr<ObjectData3D> AbstractImporter::object3D(const UnsignedInt id) {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::object3D(): no file opened", {});
     CORRADE_ASSERT(id < doObject3DCount(), "Trade::AbstractImporter::object3D(): index out of range", {});
     return doObject3D(id);
 }
 
-ObjectData3D* AbstractImporter::doObject3D(UnsignedInt) { return nullptr; }
+std::unique_ptr<ObjectData3D> AbstractImporter::doObject3D(UnsignedInt) { return nullptr; }
 
 UnsignedInt AbstractImporter::mesh2DCount() const {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::mesh2DCount(): no file opened", {});
@@ -261,13 +272,13 @@ std::string AbstractImporter::mesh2DName(const UnsignedInt id) {
 
 std::string AbstractImporter::doMesh2DName(UnsignedInt) { return {}; }
 
-MeshData2D* AbstractImporter::mesh2D(const UnsignedInt id) {
+std::optional<MeshData2D> AbstractImporter::mesh2D(const UnsignedInt id) {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::mesh2D(): no file opened", {});
     CORRADE_ASSERT(id < doMesh2DCount(), "Trade::AbstractImporter::object2D(): index out of range", {});
     return doMesh2D(id);
 }
 
-MeshData2D* AbstractImporter::doMesh2D(UnsignedInt) { return nullptr; }
+std::optional<MeshData2D> AbstractImporter::doMesh2D(UnsignedInt) { return std::nullopt; }
 
 UnsignedInt AbstractImporter::mesh3DCount() const {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::mesh3DCount(): no file opened", {});
@@ -291,13 +302,13 @@ std::string AbstractImporter::mesh3DName(const UnsignedInt id) {
 
 std::string AbstractImporter::doMesh3DName(UnsignedInt) { return {}; }
 
-MeshData3D* AbstractImporter::mesh3D(const UnsignedInt id) {
+std::optional<MeshData3D> AbstractImporter::mesh3D(const UnsignedInt id) {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::mesh3D(): no file opened", {});
     CORRADE_ASSERT(id < doMesh3DCount(), "Trade::AbstractImporter::mesh3D(): index out of range", {});
     return doMesh3D(id);
 }
 
-MeshData3D* AbstractImporter::doMesh3D(UnsignedInt) { return nullptr; }
+std::optional<MeshData3D> AbstractImporter::doMesh3D(UnsignedInt) { return std::nullopt; }
 
 UnsignedInt AbstractImporter::materialCount() const {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::materialCount(): no file opened", {});
@@ -321,13 +332,13 @@ std::string AbstractImporter::materialName(const UnsignedInt id) {
 
 std::string AbstractImporter::doMaterialName(UnsignedInt) { return {}; }
 
-AbstractMaterialData* AbstractImporter::material(const UnsignedInt id) {
+std::unique_ptr<AbstractMaterialData> AbstractImporter::material(const UnsignedInt id) {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::material(): no file opened", {});
     CORRADE_ASSERT(id < doMaterialCount(), "Trade::AbstractImporter::material(): index out of range", {});
     return doMaterial(id);
 }
 
-AbstractMaterialData* AbstractImporter::doMaterial(UnsignedInt) { return nullptr; }
+std::unique_ptr<AbstractMaterialData> AbstractImporter::doMaterial(UnsignedInt) { return nullptr; }
 
 UnsignedInt AbstractImporter::textureCount() const {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::textureCount(): no file opened", {});
@@ -351,13 +362,13 @@ std::string AbstractImporter::textureName(const UnsignedInt id) {
 
 std::string AbstractImporter::doTextureName(UnsignedInt) { return {}; }
 
-TextureData* AbstractImporter::texture(const UnsignedInt id) {
+std::optional<TextureData> AbstractImporter::texture(const UnsignedInt id) {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::texture(): no file opened", {});
     CORRADE_ASSERT(id < doTextureCount(), "Trade::AbstractImporter::texture(): index out of range", {});
     return doTexture(id);
 }
 
-TextureData* AbstractImporter::doTexture(UnsignedInt) { return nullptr; }
+std::optional<TextureData> AbstractImporter::doTexture(UnsignedInt) { return std::nullopt; }
 
 UnsignedInt AbstractImporter::image1DCount() const {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::image1DCount(): no file opened", {});
@@ -381,13 +392,13 @@ std::string AbstractImporter::image1DName(const UnsignedInt id) {
 
 std::string AbstractImporter::doImage1DName(UnsignedInt) { return {}; }
 
-ImageData1D* AbstractImporter::image1D(const UnsignedInt id) {
+std::optional<ImageData1D> AbstractImporter::image1D(const UnsignedInt id) {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::image1D(): no file opened", {});
     CORRADE_ASSERT(id < doImage1DCount(), "Trade::AbstractImporter::image1D(): index out of range", {});
     return doImage1D(id);
 }
 
-ImageData1D* AbstractImporter::doImage1D(UnsignedInt) { return nullptr; }
+std::optional<ImageData1D> AbstractImporter::doImage1D(UnsignedInt) { return std::nullopt; }
 
 UnsignedInt AbstractImporter::image2DCount() const {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::image2DCount(): no file opened", {});
@@ -411,13 +422,13 @@ std::string AbstractImporter::image2DName(const UnsignedInt id) {
 
 std::string AbstractImporter::doImage2DName(UnsignedInt) { return {}; }
 
-ImageData2D* AbstractImporter::image2D(const UnsignedInt id) {
+std::optional<ImageData2D> AbstractImporter::image2D(const UnsignedInt id) {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::image2D(): no file opened", {});
     CORRADE_ASSERT(id < doImage2DCount(), "Trade::AbstractImporter::image2D(): index out of range", {});
     return doImage2D(id);
 }
 
-ImageData2D* AbstractImporter::doImage2D(UnsignedInt) { return nullptr; }
+std::optional<ImageData2D> AbstractImporter::doImage2D(UnsignedInt) { return std::nullopt; }
 
 UnsignedInt AbstractImporter::image3DCount() const {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::image3DCount(): no file opened", {});
@@ -441,12 +452,12 @@ std::string AbstractImporter::image3DName(const UnsignedInt id) {
 
 std::string AbstractImporter::doImage3DName(UnsignedInt) { return {}; }
 
-ImageData3D* AbstractImporter::image3D(const UnsignedInt id) {
+std::optional<ImageData3D> AbstractImporter::image3D(const UnsignedInt id) {
     CORRADE_ASSERT(isOpened(), "Trade::AbstractImporter::image3D(): no file opened", {});
     CORRADE_ASSERT(id < doImage3DCount(), "Trade::AbstractImporter::image3D(): index out of range", {});
     return doImage3D(id);
 }
 
-ImageData3D* AbstractImporter::doImage3D(UnsignedInt) { return nullptr; }
+std::optional<ImageData3D> AbstractImporter::doImage3D(UnsignedInt) { return std::nullopt; }
 
 }}

src/Trade/AbstractImporter.h

@@ -28,9 +28,12 @@
  * @brief Class Magnum::Trade::AbstractImporter
  */
 
+#include <memory>
 #include <Containers/EnumSet.h>
 #include <PluginManager/AbstractPlugin.h>
 
+#include "Optional/optional.hpp"
+
 #include "Magnum.h"
 #include "magnumVisibility.h"
 #include "Trade/Trade.h"
@@ -157,10 +160,9 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
          * @brief %Scene
          * @param id        %Scene ID, from range [0, sceneCount()).
          *
-         * Returns given scene or `nullptr` if import failed. Deleting the data
+         * Returns given scene or `std::nullopt` if import failed.
-         * is user responsibility.
          */
-        SceneData* scene(UnsignedInt id);
+        std::optional<SceneData> scene(UnsignedInt id);
 
         /** @brief %Light count */
         UnsignedInt lightCount() const;
@@ -185,10 +187,9 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
          * @brief %Light
          * @param id        %Light ID, from range [0, lightCount()).
          *
-         * Returns given light or `nullptr` if importing failed. Deleting the
+         * Returns given light or `std::nullopt` if importing failed.
-         * data is user responsibility.
          */
-        LightData* light(UnsignedInt id);
+        std::optional<LightData> light(UnsignedInt id);
 
         /** @brief Camera count */
         UnsignedInt cameraCount() const;
@@ -213,10 +214,9 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
          * @brief Camera
          * @param id        Camera ID, from range [0, cameraCount()).
          *
-         * Returns given camera or `nullptr` if importing failed. Deleting the
+         * Returns given camera or `std::nullopt` if importing failed.
-         * data is user responsibility.
          */
-        CameraData* camera(UnsignedInt id);
+        std::optional<CameraData> camera(UnsignedInt id);
 
         /** @brief Two-dimensional object count */
         UnsignedInt object2DCount() const;
@@ -241,10 +241,9 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
          * @brief Two-dimensional object
          * @param id        Object ID, from range [0, object2DCount()).
          *
-         * Returns given object or `nullptr` if importing failed. Deleting the
+         * Returns given object or `nullptr` if importing failed.
-         * data is user responsibility.
          */
-        ObjectData2D* object2D(UnsignedInt id);
+        std::unique_ptr<ObjectData2D> object2D(UnsignedInt id);
 
         /** @brief Three-dimensional object count */
         UnsignedInt object3DCount() const;
@@ -269,10 +268,9 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
          * @brief Three-dimensional object
          * @param id        Object ID, from range [0, object3DCount()).
          *
-         * Returns given object or `nullptr` if importing failed. Deleting the
+         * Returns given object or `nullptr` if importing failed.
-         * data is user responsibility.
          */
-        ObjectData3D* object3D(UnsignedInt id);
+        std::unique_ptr<ObjectData3D> object3D(UnsignedInt id);
 
         /** @brief Two-dimensional mesh count */
         UnsignedInt mesh2DCount() const;
@@ -297,10 +295,9 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
          * @brief Two-dimensional mesh
          * @param id        %Mesh ID, from range [0, mesh2DCount()).
          *
-         * Returns given mesh or `nullptr` if importing failed. Deleting the
+         * Returns given mesh or `std::nullopt` if importing failed.
-         * data is user responsibility.
          */
-        MeshData2D* mesh2D(UnsignedInt id);
+        std::optional<MeshData2D> mesh2D(UnsignedInt id);
 
         /** @brief Three-dimensional mesh count */
         UnsignedInt mesh3DCount() const;
@@ -325,10 +322,9 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
          * @brief Three-dimensional mesh
          * @param id        %Mesh ID, from range [0, mesh3DCount()).
          *
-         * Returns given mesh or `nullptr` if importing failed. Deleting the
+         * Returns given mesh or `std::nullopt` if importing failed.
-         * data is user responsibility.
          */
-        MeshData3D* mesh3D(UnsignedInt id);
+        std::optional<MeshData3D> mesh3D(UnsignedInt id);
 
         /** @brief Material count */
         UnsignedInt materialCount() const;
@@ -353,10 +349,9 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
          * @brief Material
          * @param id        Material ID, from range [0, materialCount()).
          *
-         * Returns given material or `nullptr` if importing failed. Deleting
+         * Returns given material or `nullptr` if importing failed.
-         * the data is user responsibility.
          */
-        AbstractMaterialData* material(UnsignedInt id);
+        std::unique_ptr<AbstractMaterialData> material(UnsignedInt id);
 
         /** @brief %Texture count */
         UnsignedInt textureCount() const;
@@ -381,10 +376,9 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
          * @brief %Texture
          * @param id        %Texture ID, from range [0, textureCount()).
          *
-         * Returns given texture or `nullptr` if importing failed. Deleting the
+         * Returns given texture or `std::nullopt` if importing failed.
-         * data is user responsibility.
          */
-        TextureData* texture(UnsignedInt id);
+        std::optional<TextureData> texture(UnsignedInt id);
 
         /** @brief One-dimensional image count */
         UnsignedInt image1DCount() const;
@@ -409,10 +403,9 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
          * @brief One-dimensional image
          * @param id        %Image ID, from range [0, image1DCount()).
          *
-         * Returns given image or `nullptr` if importing failed. Deleting the
+         * Returns given image or `std::nullopt` if importing failed.
-         * data is user responsibility.
          */
-        ImageData1D* image1D(UnsignedInt id);
+        std::optional<ImageData1D> image1D(UnsignedInt id);
 
         /** @brief Two-dimensional image count */
         UnsignedInt image2DCount() const;
@@ -437,10 +430,9 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
          * @brief Two-dimensional image
          * @param id        %Image ID, from range [0, image2DCount()).
          *
-         * Returns given image or `nullptr` if importing failed. Deleting the
+         * Returns given image or `std::nullopt` if importing failed.
-         * data is user responsibility.
          */
-        ImageData2D* image2D(UnsignedInt id);
+        std::optional<ImageData2D> image2D(UnsignedInt id);
 
         /** @brief Three-dimensional image count */
         UnsignedInt image3DCount() const;
@@ -465,10 +457,9 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
          * @brief Three-dimensional image
          * @param id        %Image ID, from range [0, image3DCount()).
          *
-         * Returns given image or `nullptr` if importing failed. Deleting the
+         * Returns given image or `std::nullopt` if importing failed.
-         * data is user responsibility.
          */
-        ImageData3D* image3D(UnsignedInt id);
+        std::optional<ImageData3D> image3D(UnsignedInt id);
 
         /*@}*/
 
@@ -510,7 +501,7 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
         virtual std::string doSceneName(UnsignedInt id);
 
         /** @brief Implementation for scene() */
-        virtual SceneData* doScene(UnsignedInt id);
+        virtual std::optional<SceneData> doScene(UnsignedInt id);
 
         /** @brief Implementation for lightCount() */
         virtual UnsignedInt doLightCount() const;
@@ -522,7 +513,7 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
         virtual std::string doLightName(UnsignedInt id);
 
         /** @brief Implementation for light() */
-        virtual LightData* doLight(UnsignedInt id);
+        virtual std::optional<LightData> doLight(UnsignedInt id);
 
         /** @brief Implementation for cameraCount() */
         virtual UnsignedInt doCameraCount() const;
@@ -534,7 +525,7 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
         virtual std::string doCameraName(UnsignedInt id);
 
         /** @brief Implementation for camera() */
-        virtual CameraData* doCamera(UnsignedInt id);
+        virtual std::optional<CameraData> doCamera(UnsignedInt id);
 
         /** @brief Implementation for object2DCount() */
         virtual UnsignedInt doObject2DCount() const;
@@ -546,7 +537,7 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
         virtual std::string doObject2DName(UnsignedInt id);
 
         /** @brief Implementation for object2D() */
-        virtual ObjectData2D* doObject2D(UnsignedInt id);
+        virtual std::unique_ptr<ObjectData2D> doObject2D(UnsignedInt id);
 
         /** @brief Implementation for object3DCount() */
         virtual UnsignedInt doObject3DCount() const;
@@ -558,7 +549,7 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
         virtual std::string doObject3DName(UnsignedInt id);
 
         /** @brief Implementation for object3D() */
-        virtual ObjectData3D* doObject3D(UnsignedInt id);
+        virtual std::unique_ptr<ObjectData3D> doObject3D(UnsignedInt id);
 
         /** @brief Implementation for mesh2DCount() */
         virtual UnsignedInt doMesh2DCount() const;
@@ -570,7 +561,7 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
         virtual std::string doMesh2DName(UnsignedInt id);
 
         /** @brief Implementation for mesh2D() */
-        virtual MeshData2D* doMesh2D(UnsignedInt id);
+        virtual std::optional<MeshData2D> doMesh2D(UnsignedInt id);
 
         /** @brief Implementation for mesh3DCount() */
         virtual UnsignedInt doMesh3DCount() const;
@@ -582,7 +573,7 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
         virtual std::string doMesh3DName(UnsignedInt id);
 
         /** @brief Implementation for mesh3D() */
-        virtual MeshData3D* doMesh3D(UnsignedInt id);
+        virtual std::optional<MeshData3D> doMesh3D(UnsignedInt id);
 
         /** @brief Implementation for materialCount() */
         virtual UnsignedInt doMaterialCount() const;
@@ -594,7 +585,7 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
         virtual std::string doMaterialName(UnsignedInt id);
 
         /** @brief Implementation for material() */
-        virtual AbstractMaterialData* doMaterial(UnsignedInt id);
+        virtual std::unique_ptr<AbstractMaterialData> doMaterial(UnsignedInt id);
 
         /** @brief Implementation for textureCount() */
         virtual UnsignedInt doTextureCount() const;
@@ -606,7 +597,7 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
         virtual std::string doTextureName(UnsignedInt id);
 
         /** @brief Implementation for texture() */
-        virtual TextureData* doTexture(UnsignedInt id);
+        virtual std::optional<TextureData> doTexture(UnsignedInt id);
 
         /** @brief Implementation for image1DCount() */
         virtual UnsignedInt doImage1DCount() const;
@@ -618,7 +609,7 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
         virtual std::string doImage1DName(UnsignedInt id);
 
         /** @brief Implementation for image1D() */
-        virtual ImageData1D* doImage1D(UnsignedInt id);
+        virtual std::optional<ImageData1D> doImage1D(UnsignedInt id);
 
         /** @brief Implementation for image2DCount() */
         virtual UnsignedInt doImage2DCount() const;
@@ -630,7 +621,7 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
         virtual std::string doImage2DName(UnsignedInt id);
 
         /** @brief Implementation for image2D() */
-        virtual ImageData2D* doImage2D(UnsignedInt id);
+        virtual std::optional<ImageData2D> doImage2D(UnsignedInt id);
 
         /** @brief Implementation for image3DCount() */
         virtual UnsignedInt doImage3DCount() const;
@@ -642,7 +633,7 @@ class MAGNUM_EXPORT AbstractImporter: public PluginManager::AbstractPlugin {
         virtual std::string doImage3DName(UnsignedInt id);
 
         /** @brief Implementation for image3D() */
-        virtual ImageData3D* doImage3D(UnsignedInt id);
+        virtual std::optional<ImageData3D> doImage3D(UnsignedInt id);
 };
 
 CORRADE_ENUMSET_OPERATORS(AbstractImporter::Features)

src/Trade/CameraData.h

@@ -35,12 +35,7 @@ namespace Magnum { namespace Trade {
 /**
 @brief %Camera data
 */
-class MAGNUM_EXPORT CameraData {
+class MAGNUM_EXPORT CameraData {};
-    CameraData(const CameraData&) = delete;
-    CameraData(CameraData&&) = delete;
-    CameraData& operator=(const CameraData&) = delete;
-    CameraData& operator=(CameraData&&) = delete;
-};
 
 }}
 

src/Trade/LightData.h

@@ -35,12 +35,7 @@ namespace Magnum { namespace Trade {
 /**
 @brief %Light data
 */
-class MAGNUM_EXPORT LightData {
+class MAGNUM_EXPORT LightData {};
-    LightData(const LightData&) = delete;
-    LightData(LightData&&) = delete;
-    LightData& operator=(const LightData&) = delete;
-    LightData& operator=(LightData&&) = delete;
-};
 
 }}