Putting calls of temporary member functors in brackets causes an error, "error:
`type name' declared as function returning a function".
The following code:
struct S
{
struct Member_functor
{
void operator () ()
{
}
};
};
int main( int argc, char* argv[] )
{
S::Member_functor()(); // OK
( S::Member_functor()() ); // error: `type name' declared as function
returning a function
return 0;
}
produces this error using Cygwin gcc 3.4.4 on a WindowsXP Pro sp2 PC:
J:\>g++ -o gcc_test2.exe gcc_test2.cpp -Wall -save-temps -v
Reading specs from /usr/lib/gcc/i686-pc-cygwin/3.4.4/specs
Configured with: /gcc/gcc-3.4.4/gcc-3.4.4-1/configure --verbose --prefix=/usr
--exec-prefix=/usr --sysconfdir=/etc --libdir=/usr/lib --libexecdir=/usr/lib
--mandir=/usr/share/man --infodir=/usr/share/info
--enable-languages=c,ada,c++,d,f77,java,objc --enable-nls
--without-included-gettext --enable-version-specific-runtime-libs --without-x
--enable-libgcj --disable-java-awt --with-system-zlib --enable-interpreter
--disable-libgcj-debug --enable-threads=posix --enable-java-gc=boehm
--disable-win32-registry --enable-sjlj-exceptions --enable-hash-synchronization
--enable-libstdcxx-debug : (reconfigured)
Thread model: posix
gcc version 3.4.4 (cygming special) (gdc 0.12, using dmd 0.125)
/usr/lib/gcc/i686-pc-cygwin/3.4.4/cc1plus.exe -E -quiet -v -D__CYGWIN32__
-D__CYGWIN__ -Dunix -D__unix__ -D__unix -idirafter
/usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../../include/w32api -idirafter
/usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../../i686-pc-cygwin/lib/../../include/w32api
gcc_test2.cpp -mtune=pentiumpro -Wall -o gcc_test2.ii
ignoring nonexistent directory "/usr/local/include"
ignoring nonexistent directory
"/usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../../i686-pc-cygwin/include"
ignoring duplicate directory
"/usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../../i686-pc-cygwin/lib/../../include/w32api"
#include "..." search starts here:
#include <...> search starts here:
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/i686-pc-cygwin
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/backward
/usr/lib/gcc/i686-pc-cygwin/3.4.4/include
/usr/include
/usr/lib/gcc/i686-pc-cygwin/3.4.4/../../../../include/w32api
End of search list.
/usr/lib/gcc/i686-pc-cygwin/3.4.4/cc1plus.exe -fpreprocessed gcc_test2.ii
-quiet -dumpbase gcc_test2.cpp -mtune=pentiumpro -auxbase gcc_test2 -Wall
-version -o gcc_test2.s
GNU C++ version 3.4.4 (cygming special) (gdc 0.12, using dmd 0.125)
(i686-pc-cygwin)
compiled by GNU C version 3.4.4 (cygming special) (gdc 0.12, using dmd
0.125).
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
gcc_test2.cpp: In function `int main(int, char**)':
gcc_test2.cpp:14: error: `type name' declared as function returning a function
gcc_test2.cpp:14: error: `type name' declared as function returning a function
The same applies to functors returning values.
The contents of the preprocessed file is given below:
# 1 "gcc_test2.cpp"
# 1 "<built-in>"
# 1 "<command line>"
# 1 "gcc_test2.cpp"
struct S
{
struct Member_functor
{
void operator () ()
{
}
};
};
int main( int argc, char* argv[] )
{
S::Member_functor()();
( S::Member_functor()() );
return 0;
}
--
Summary: Cannot put temporary member functor calls inside
brackets
Product: gcc
Version: 3.4.4
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: lloyd dot reed at vistec-semi dot com
GCC host triplet: i686-pc-cygwin
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29234
