boostorg/unordered
1
0
Fork 1
mirror of https://github.com/boostorg/unordered.git synced 2025-07-29 19:07:15 +02:00
Code Issues Packages Projects Releases Wiki Activity

Unordered: Alternative member detection.

Browse Source 
Hopefully the Sun compiler will like this.

[SVN r73757]
This commit is contained in:
Daniel James
2011-08-14 18:53:50 +00:00
parent 5f622027cd
commit 431f2abfee
1 changed files with 13 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files

20
include/boost/unordered/detail/allocator_helpers.hpp
View File

@ -85,21 +85,27 @@ namespace boost { namespace unordered { namespace detail {
template<typename T> convertible_from_anything(T const&);
};
typedef char (&no_type)[1];
typedef char (&yes_type)[2];
template <typename T> struct sfinae {
typedef yes_type type;
};
// Infrastructure for providing a default type for Tp::tname if absent.
#define BOOST_DEFAULT_TYPE_TMPLT(tname) \
template <typename Tp, typename Default> \
struct default_type_ ## tname { \
template <typename T> \
static BOOST_DEDUCED_TYPENAME sfinae< \
BOOST_DEDUCED_TYPENAME T::tname>::type test(int); \
template <typename T> \
static no_type test(...); \
\
template <typename X> \
static char test(int, BOOST_DEDUCED_TYPENAME X::tname*); \
\
template <typename X> \
static int test(convertible_from_anything, void*); \
enum { value = sizeof(test<Tp>(0)) == sizeof(yes_type) }; \
\
struct DefaultWrap { typedef Default tname; }; \
\
static const bool value = (1 == sizeof(test<Tp>(0, 0))); \
\
typedef BOOST_DEDUCED_TYPENAME \
boost::detail::if_true<value>:: \
BOOST_NESTED_TEMPLATE then<Tp, DefaultWrap> \