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[Bug c++/52374] New: [C++11] Fails to transform id-expression into dependent base member access in lambda expression
- From: "ai.azuma at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Fri, 24 Feb 2012 16:45:10 +0000
- Subject: [Bug c++/52374] New: [C++11] Fails to transform id-expression into dependent base member access in lambda expression
- Auto-submitted: auto-generated
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52374
Bug #: 52374
Summary: [C++11] Fails to transform id-expression into
dependent base member access in lambda expression
Classification: Unclassified
Product: gcc
Version: 4.7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: ai.azuma@gmail.com
Created attachment 26742
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26742
Output of -v option and preprocessed file
In the lambda expression's compound statement, id-expressions referring to
non-static members should be transformed into class member access expressions
by prefixing `(*this).'. However, GCC fails the transformation when
id-expressions involved are qualified-ids and refer to dependent base members.
A test case is as follows;
////////////////////////////////////////////////////////////////////
struct B
{
int get() const { return 42; }
};
template<typename X>
struct D
: public X
{
int get() const { return [this]() -> int { return X::get(); }(); }
};
int main()
{
D<B> d;
d.get();
}
////////////////////////////////////////////////////////////////////
For the above mentioned well-formed code, 4.7.0 20120218 (experimental) with
-std=c++11 complains as follows;
main.cpp: In instantiation of 'D<X>::get() const [with X = B]::<lambda()>':
main.cpp:10:29: required from 'struct D<X>::get() const [with X =
B]::<lambda()>'
main.cpp:10:65: required from 'int D<X>::get() const [with X = B]'
main.cpp:16:9: required from here
main.cpp:10:60: error: cannot call member function 'int B::get() const' without
object
`X::get' in the lambda expression should be implicitly transformed into
`(*this).X::get', and the test case should compile successfully.