Re: [Boost-users] Newbie: Compiling multi filed programs

AMDG Pete wrote:

Still trying to get a grip on Boost with some toy problems. I have a very simple program that multiplies two vectors. It worked as a single file program, but doesn't work as a multi file program. I'm finding it difficult to deal with impressive looking templates in the compiler error messages. This is on Linux, g++, Debian testing.

<snip>

Since 09-driver.o and 09-prob.o are being linked together, I'm guessing there's something wrong with the function signature?

Can some kind soul give me a few hints on how to make this work?

Here's the problem: In 09-driver.cpp the compiler knows that it needs mult_vector_vector but does not have its definition In 09-prob.cpp the compiler has the definition of mult_vector_vector, but does not know that it needs to be instantiated with boost::numeric::ublas::vector<double> You have two options: a) put the definition of mult_vector_vector in 09-prob.h. This is the standard solution. b) add the following explicit instantiation in 09-prob.cpp typedef boost::numeric::ublas::vector<double> vec_t; template vector_matrix_binary_traits< vec_t, vec_t,scalar_multiplies

::result_type mult_vector_vector( vec_t bra, vec_t ket );

In Christ, Steven Watanabe