compile error with Boost Function object and templated function (Intel C++ compiler)

[Faheem Mitha]

Hi,

The following bit of code compiles fine with gcc 3.3 or later, but has
problems with the Intel C++ compiler version 9.1, which produces the
following error message.

Is this a compiler bug, or is there something wrong with the code?

If the former, I'd be grateful for suggestions of a workaround, and if
the latter, please tell me what I'm doing wrong.

Note that the corresponding version with no templates compiles without
problems.

Thanks in advance. Faheem.

**************************************************************************

icpc -o foo.o -c -Wall -Werror -g -wd383,810,981,1418 cxxlib-icc
-DBOOST_RAND -I/usr/local/include/boost-1_33_1 \foo.cpp

foo.cpp(12): error: no operator "=" matches these operands operand
types are: boost::function<int (), std::allocator<void>> =
<unknown-type>
choice = &rchoice<dim>;
^
*************************************************************
#include <boost/function.hpp>

template<int dim>
int rchoice()
{
return 1;
}

template<int dim> int foo(void)
{
boost::function<int ()> choice;
choice = &rchoice<dim>;
return choice();
}

int main()
{
return foo<2>();
}
***************************************************************

 

[mlimber]

Hi,

The following bit of code compiles fine with gcc 3.3 or later, but has
problems with the Intel C++ compiler version 9.1, which produces the
following error message.

Is this a compiler bug, or is there something wrong with the code?

If the former, I'd be grateful for suggestions of a workaround, and if
the latter, please tell me what I'm doing wrong.

Note that the corresponding version with no templates compiles without
problems.

Thanks in advance. Faheem.

**************************************************************************

icpc -o foo.o -c -Wall -Werror -g -wd383,810,981,1418 cxxlib-icc
-DBOOST_RAND -I/usr/local/include/boost-1_33_1 \foo.cpp

foo.cpp(12): error: no operator "=" matches these operands operand
types are: boost::function<int (), std::allocator<void>> =
<unknown-type>
choice = &rchoice<dim>;
^
*************************************************************
#include <boost/function.hpp>

template<int dim>
int rchoice()
{
return 1;
}

template<int dim> int foo(void)
{
boost::function<int ()> choice;
choice = &rchoice<dim>;
return choice();
}

int main()
{
return foo<2>();
}
***************************************************************

Changing the header to <functional> and boost::function to
std::tr1::function, the code compiles fine at Dinkum's online test with
both MS VC++8 and EDG, so I'd say it's an Intel problem. In that case,
you'll want to post to a compiler-specific newsgroup or forum (in your
case, something to do with Intel's compiler) for a work-around (see
http://www.parashift.com/c++-faq-lite/how-to-post.html#faq-5.9).

Cheers! --M

 

[Faheem Mitha]

Changing the header to <functional> and boost::function to
std::tr1::function, the code compiles fine at Dinkum's online test
with both MS VC++8 and EDG, so I'd say it's an Intel problem. In
that case, you'll want to post to a compiler-specific newsgroup or
forum (in your case, something to do with Intel's compiler) for a
work-around (see
http://www.parashift.com/c++-faq-lite/how-to-post.html#faq-5.9).

Thanks for the information. I don't quite get the bit about changing
the header and boost::function, but if it is really a compiler bug,
that is unfortunate.

Faheem.