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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 , boost::true_type, boost::false_type>::type
{}; {};
template <typename T, typename U>
struct is_optional_constructible : boost::is_constructible<T, U>
{};
#else #else
#define BOOST_OPTIONAL_DETAIL_NO_IS_CONSTRUCTIBLE_TRAIT #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 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 #endif // is_convertible condition
template <typename T, typename U> 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. // Requires a valid conversion from U to T.
// Can throw if T::T(U const&) does // Can throw if T::T(U const&) does
template<class U> 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() base()
{ {
@ -825,7 +834,8 @@ class optional : public optional_detail::optional_base<T>
// Requires a valid conversion from U to T. // Requires a valid conversion from U to T.
// Can throw if T::T(U&&) does // Can throw if T::T(U&&) does
template<class U> 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() base()
{ {

26
test/optional_test_convert_from_T.cpp
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@ -23,6 +23,29 @@
using boost::optional; using boost::optional;
using boost::none; 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() void test_optional_optional_T()
{ {
optional<int> oi1 (1), oiN; optional<int> oi1 (1), oiN;
@ -39,6 +62,7 @@ void test_optional_optional_T()
int main() int main()
{ {
test_optional_optional_T(); test_optional_optional_T();
test_optional_of_superconverting_T();
return boost::report_errors(); return boost::report_errors();
} }

17
test/optional_test_sfinae_friendly_value_ctor.cpp
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@ -27,11 +27,20 @@ struct Resource
explicit Resource(const X&) {} explicit Resource(const X&) {}
}; };
BOOST_STATIC_ASSERT(( boost::is_constructible<Resource, const X&>::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<Resource, const Y&>::value ));
BOOST_STATIC_ASSERT(( boost::is_constructible<optional<Resource>, const X&>::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 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 #endif