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Diffstat (limited to 'boost/optional/detail/optional_reference_spec.hpp')
-rw-r--r--boost/optional/detail/optional_reference_spec.hpp78
1 files changed, 64 insertions, 14 deletions
diff --git a/boost/optional/detail/optional_reference_spec.hpp b/boost/optional/detail/optional_reference_spec.hpp
index ba3951af7b..ce558755a2 100644
--- a/boost/optional/detail/optional_reference_spec.hpp
+++ b/boost/optional/detail/optional_reference_spec.hpp
@@ -44,6 +44,23 @@ BOOST_DEDUCED_TYPENAME boost::remove_reference<T>::type& forward_reference(T&& r
#endif // BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
+
+template <class T>
+struct is_const_integral
+{
+ static const bool value = boost::is_const<T>::value && boost::is_integral<T>::value;
+};
+
+template <class T>
+struct is_const_integral_bad_for_conversion
+{
+#if (!defined BOOST_OPTIONAL_CONFIG_ALLOW_BINDING_TO_RVALUES) && (defined BOOST_OPTIONAL_CONFIG_NO_PROPER_CONVERT_FROM_CONST_INT)
+ static const bool value = boost::is_const<T>::value && boost::is_integral<T>::value;
+#else
+ static const bool value = false;
+#endif
+};
+
template <class From>
void prevent_assignment_from_false_const_integral()
{
@@ -51,12 +68,13 @@ void prevent_assignment_from_false_const_integral()
#ifdef BOOST_OPTIONAL_CONFIG_NO_PROPER_ASSIGN_FROM_CONST_INT
// MSVC compiler without rvalue refernces: we need to disable the asignment from
// const integral lvalue reference, as it may be an invalid temporary
- BOOST_STATIC_ASSERT_MSG(!(boost::is_const<From>::value && boost::is_integral<From>::value),
+ BOOST_STATIC_ASSERT_MSG(!is_const_integral<From>::value,
"binding const lvalue references to integral types is disabled in this compiler");
#endif
#endif
}
+
template <class T>
struct is_optional_
{
@@ -75,6 +93,21 @@ struct is_no_optional
static const bool value = !is_optional_<BOOST_DEDUCED_TYPENAME boost::decay<T>::type>::value;
};
+
+template <class T, class U>
+ struct is_same_decayed
+ {
+ static const bool value = ::boost::is_same<T, BOOST_DEDUCED_TYPENAME ::boost::remove_reference<U>::type>::value
+ || ::boost::is_same<T, const BOOST_DEDUCED_TYPENAME ::boost::remove_reference<U>::type>::value;
+ };
+
+template <class T, class U>
+struct no_unboxing_cond
+{
+ static const bool value = is_no_optional<U>::value && !is_same_decayed<T, U>::value;
+};
+
+
} // namespace detail
template <class T>
@@ -94,13 +127,21 @@ public:
optional(none_t) BOOST_NOEXCEPT : ptr_() {}
template <class U>
- explicit optional(const optional<U&>& rhs) BOOST_NOEXCEPT : ptr_(rhs.ptr_) {}
- optional(const optional& rhs) BOOST_NOEXCEPT : ptr_(rhs.ptr_) {}
+ explicit optional(const optional<U&>& rhs) BOOST_NOEXCEPT : ptr_(rhs.get_ptr()) {}
+ optional(const optional& rhs) BOOST_NOEXCEPT : ptr_(rhs.get_ptr()) {}
+ // the following two implement a 'conditionally explicit' constructor: condition is a hack for buggy compilers with srewed conversion construction from const int
+ template <class U>
+ explicit optional(U& rhs, BOOST_DEDUCED_TYPENAME boost::enable_if_c<detail::is_same_decayed<T, U>::value && detail::is_const_integral_bad_for_conversion<U>::value>::type* = 0) BOOST_NOEXCEPT
+ : ptr_(boost::addressof(rhs)) {}
+
+ template <class U>
+ optional(U& rhs, BOOST_DEDUCED_TYPENAME boost::enable_if_c<detail::is_same_decayed<T, U>::value && !detail::is_const_integral_bad_for_conversion<U>::value>::type* = 0) BOOST_NOEXCEPT
+ : ptr_(boost::addressof(rhs)) {}
- optional& operator=(const optional& rhs) BOOST_NOEXCEPT { ptr_ = rhs.ptr_; return *this; }
+ optional& operator=(const optional& rhs) BOOST_NOEXCEPT { ptr_ = rhs.get_ptr(); return *this; }
template <class U>
- optional& operator=(const optional<U&>& rhs) BOOST_NOEXCEPT { ptr_ = rhs.ptr_; return *this; }
+ optional& operator=(const optional<U&>& rhs) BOOST_NOEXCEPT { ptr_ = rhs.get_ptr(); return *this; }
optional& operator=(none_t) BOOST_NOEXCEPT { ptr_ = 0; return *this; }
@@ -121,8 +162,10 @@ public:
#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
+ optional(T&& /* rhs */) BOOST_NOEXCEPT { detail::prevent_binding_rvalue<T&&>(); }
+
template <class R>
- optional(R&& r, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<R> >::type* = 0) BOOST_NOEXCEPT
+ optional(R&& r, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::no_unboxing_cond<T, R> >::type* = 0) BOOST_NOEXCEPT
: ptr_(boost::addressof(r)) { detail::prevent_binding_rvalue<R>(); }
template <class R>
@@ -154,19 +197,26 @@ public:
#else // BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
+
+ // the following two implement a 'conditionally explicit' constructor
+ template <class U>
+ explicit optional(U& v, BOOST_DEDUCED_TYPENAME boost::enable_if_c<detail::no_unboxing_cond<T, U>::value && detail::is_const_integral_bad_for_conversion<U>::value >::type* = 0) BOOST_NOEXCEPT
+ : ptr_(boost::addressof(v)) { }
+
template <class U>
- optional(U& v, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<U> >::type* = 0) BOOST_NOEXCEPT : ptr_(boost::addressof(v)) { }
+ optional(U& v, BOOST_DEDUCED_TYPENAME boost::enable_if_c<detail::no_unboxing_cond<T, U>::value && !detail::is_const_integral_bad_for_conversion<U>::value >::type* = 0) BOOST_NOEXCEPT
+ : ptr_(boost::addressof(v)) { }
template <class U>
- optional(bool cond, U& v, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<U> >::type* = 0) BOOST_NOEXCEPT : ptr_(cond ? boost::addressof(v) : 0) {}
+ optional(bool cond, U& v, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<U> >::type* = 0) BOOST_NOEXCEPT : ptr_(cond ? boost::addressof(v) : 0) {}
template <class U>
- BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<U>, optional<T&>&>::type
- operator=(U& v) BOOST_NOEXCEPT
- {
- detail::prevent_assignment_from_false_const_integral<U>();
- ptr_ = boost::addressof(v); return *this;
- }
+ BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<U>, optional<T&>&>::type
+ operator=(U& v) BOOST_NOEXCEPT
+ {
+ detail::prevent_assignment_from_false_const_integral<U>();
+ ptr_ = boost::addressof(v); return *this;
+ }
template <class U>
void emplace(U& v, BOOST_DEDUCED_TYPENAME boost::enable_if<detail::is_no_optional<U> >::type* = 0) BOOST_NOEXCEPT