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Fix #12563

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This commit is contained in:
Andrzej Krzemienski
2016-11-19 14:57:40 +01:00
parent 8d69e99e78
commit 7ea2ca6c40
3 changed files with 50 additions and 7 deletions
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14
include/boost/optional/optional.hpp
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@ -745,6 +745,10 @@ struct is_convertible_to_T_or_factory
, boost::true_type, boost::false_type>::type
{};
template <typename T, typename U>
struct is_optional_constructible : boost::is_constructible<T, U>
{};
#else
#define BOOST_OPTIONAL_DETAIL_NO_IS_CONSTRUCTIBLE_TRAIT
@ -753,6 +757,10 @@ template <typename, typename>
struct is_convertible_to_T_or_factory : boost::true_type
{};
template <typename T, typename U>
struct is_optional_constructible : boost::true_type
{};
#endif // is_convertible condition
template <typename T, typename U>
@ -812,7 +820,8 @@ class optional : public optional_detail::optional_base<T>
// Requires a valid conversion from U to T.
// Can throw if T::T(U const&) does
template<class U>
explicit optional ( optional<U> const& rhs )
explicit optional ( optional<U> const& rhs,
typename boost::enable_if< optional_detail::is_optional_constructible<T, U const&> >::type* = 0)
:
base()
{
@ -825,7 +834,8 @@ class optional : public optional_detail::optional_base<T>
// Requires a valid conversion from U to T.
// Can throw if T::T(U&&) does
template<class U>
explicit optional ( optional<U> && rhs )
explicit optional ( optional<U> && rhs,
typename boost::enable_if< optional_detail::is_optional_constructible<T, U> >::type* = 0 )
:
base()
{

24
test/optional_test_convert_from_T.cpp
View File

@ -23,6 +23,29 @@
using boost::optional;
using boost::none;
template <typename U>
struct superconv
{
#ifndef BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
template <typename T>
superconv(T&&) { BOOST_STATIC_ASSERT(sizeof(T) == 0); }
#else
template <typename T>
superconv(const T&) { BOOST_STATIC_ASSERT(sizeof(T) == 0); }
template <typename T>
superconv( T&) { BOOST_STATIC_ASSERT(sizeof(T) == 0); }
#endif
superconv() {}
};
void test_optional_of_superconverting_T() // compile-time test
{
superconv<optional<int> > s;
superconv<optional<int> > & rs = s;
optional<superconv<optional<int> > > os = rs;
}
void test_optional_optional_T()
{
optional<int> oi1 (1), oiN;
@ -39,6 +62,7 @@ void test_optional_optional_T()
int main()
{
test_optional_optional_T();
test_optional_of_superconverting_T();
return boost::report_errors();
}

17
test/optional_test_sfinae_friendly_value_ctor.cpp
View File

@ -27,11 +27,20 @@ struct Resource
explicit Resource(const X&) {}
};
BOOST_STATIC_ASSERT(( boost::is_constructible<Resource, const X&>::value));
BOOST_STATIC_ASSERT((!boost::is_constructible<Resource, const Y&>::value));
BOOST_STATIC_ASSERT(( boost::is_constructible<Resource, const X&>::value ));
BOOST_STATIC_ASSERT(( !boost::is_constructible<Resource, const Y&>::value ));
BOOST_STATIC_ASSERT(( boost::is_constructible<optional<Resource>, const X&>::value));
BOOST_STATIC_ASSERT((!boost::is_constructible<optional<Resource>, const Y&>::value));
BOOST_STATIC_ASSERT(( boost::is_constructible<optional<Resource>, const X&>::value ));
BOOST_STATIC_ASSERT(( !boost::is_constructible<optional<Resource>, const Y&>::value ));
BOOST_STATIC_ASSERT(( boost::is_constructible< optional< optional<int> >, optional<int> >::value ));
BOOST_STATIC_ASSERT(( !boost::is_constructible< optional<int>, optional< optional<int> > >::value ));
BOOST_STATIC_ASSERT(( boost::is_constructible< optional< optional<int> >, const optional<int>& >::value ));
BOOST_STATIC_ASSERT(( !boost::is_constructible< optional<int>, const optional< optional<int> >& >::value ));
BOOST_STATIC_ASSERT(( boost::is_constructible<optional<Resource>, const optional<X>&>::value ));
BOOST_STATIC_ASSERT(( !boost::is_constructible<optional<Resource>, const optional<Y>&>::value ));
#endif