| 12345678910111213141516171819202122232425262728293031323334353637383940414243 |
- From https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87822
- Author: Jonathan Wakely <[email protected]>
- Date: Wed Oct 31 13:03:25 2018 +0000
- PR libstdc++/87822 fix layout change for nested std::pair
-
- The introduction of the empty __pair_base base class for PR 86751
- changed the layout of std::pair<std::pair<...>, ...>. The outer pair and
- its first member both have a base class of the same type, which cannot
- exist at the same address. This causes the first member to be at a
- non-zero offset.
-
- The solution is to make the base class depend on the template
- parameters, so that each pair type has a different base class type,
- which allows the base classes of the outer pair and its first member to
- have the same address.
-
- PR libstdc++/87822
- * include/bits/stl_pair.h (__pair_base): Change to class template.
- (pair): Make base class type depend on template parameters.
- diff --git a/libstdc++-v3/include/bits/stl_pair.h b/libstdc++-v3/include/bits/stl_pair.h
- index a30b630b4fd..5a4823ab018 100644
- --- a/libstdc++-v3/include/bits/stl_pair.h
- +++ b/libstdc++-v3/include/bits/stl_pair.h
- @@ -183,7 +183,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
- };
- #endif // C++11
-
- - class __pair_base
- + template<typename _U1, typename _U2> class __pair_base
- {
- #if __cplusplus >= 201103L
- template<typename _T1, typename _T2> friend struct pair;
- @@ -202,7 +202,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
- */
- template<typename _T1, typename _T2>
- struct pair
- - : private __pair_base
- + : private __pair_base<_T1, _T2>
- {
- typedef _T1 first_type; /// @c first_type is the first bound type
- typedef _T2 second_type; /// @c second_type is the second bound type
|
