Re: [Boost-users] [proto] extends example not compiling

Subject: Re: [Boost-users] [proto] extends example not compiling
From: Eric Niebler (eric_at_[hidden])
Date: 2009-12-16 05:01:06

Eric Niebler wrote:
> alfC wrote:
>> Is this example, contained in the boost.Proto manual supposed to
>> compile?
>>
>> #include<complex>
>> #include <boost/proto/core.hpp>
>> #include <boost/proto/context.hpp>
>> #include <boost/proto/debug.hpp>
>> #include<boost/proto/extends.hpp>
>>
>> template<class T, class Dummy = boost::proto::is_proto_expr>
>> struct my_complex
>> {
>>     BOOST_PROTO_EXTENDS(
>>         typename boost::proto::terminal<std::complex<T> >::type
>>       , my_complex<T>
>>       , boost::proto::default_domain
>>     )
>> };
>>
>> int main()
>> {
>>     my_complex<int> c0, c1;
>>
>>     c0 + c1; // OK, operator+ found now!
>> }
>>
>> I get this error (with gcc 4.3 and gcc 4.4):
>> proto_complex.cpp:10: error: expected nested-name-specifier before
>> ‘typename’
>> proto_complex.cpp:10: error: two or more data types in declaration of
>> ‘proto_base_expr’
>> proto_complex.cpp:10: error: ‘proto_base_expr’ has not been declared
>> proto_complex.cpp:10: error: ‘proto_base_expr’ has not been declared
> 
> 
> I seem to recall seeing this error before with gcc. I think it's a 
> compiler bug, but I haven't investigated.

I take it back. This is a bug in Proto. I'll fix it.

-- 
Eric Niebler
BoostPro Computing
http://www.boostpro.com