http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54277
Bug #: 54277
Summary: Template class member referred to with implicit this
inside lambda is incorrectly const-qualified
Classification: Unclassified
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: tra...@gockelhut.com
Created attachment 28025
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28025
reproduce -- fails in 4.7.0, works in 4.6.3
When a template class attempts to call a member's member function inside of a
lambda function AND the member is referred to through an implicit this, the
member will be erroneously const-qualified.
struct Used
{
void foo() { }
};
template <typename>
struct S
{
Used x;
void bar()
{
auto f = [this] { x.foo(); };
f();
}
};
Yields the following compilation error with g++ 4.7:
capture-this-const.cpp: In lambda function:
capture-this-const.cpp:13:27: error: no matching function for call to
‘Used::foo() const’
capture-this-const.cpp:13:27: note: candidate is:
capture-this-const.cpp:3:7: note: void Used::foo() <near match>
capture-this-const.cpp:3:7: note: no known conversion for implicit ‘this’
parameter from ‘const Used*’ to ‘Used*’
---
This can be compiled properly by explicitly adding this->:
auto f = [this] { this->x.foo(); };
---
$> g++ -v
Using built-in specs.
COLLECT_GCC=g++-4.7
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.7/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro
4.7.0-7ubuntu3' --with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs
--enable-languages=c,c++,go,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-4.7 --enable-shared --enable-linker-build-id
--with-system-zlib --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.7
--libdir=/usr/lib --enable-nls --disable-bootstrap --with-sysroot=/
--enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes
--enable-gnu-unique-object --enable-plugin --enable-objc-gc --disable-werror
--with-arch-32=i686 --with-tune=generic --enable-checking=release
--build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.7.0 (Ubuntu/Linaro 4.7.0-7ubuntu3)
