Re: [Boost-users] tuple

On Thu, 22 Apr 2010, luca formaggia wrote:

Hello,

someone could tell me what is wrong in this piece of code

#include "boost/tuple/tuple.hpp" using namespace boost::tuples; int main(){         tuple t2();         get<0>(t2)=int(10); }

I get the following error message:

g++ try.cpp try.cpp: In function ‘int main()’: try.cpp:5: error: no matching function for call to ‘get(boost::tuples::tuple (&)())

In the tutorial it is written that tuple t2() should construct the object via the default constructor.

This syntax is not correct. "tuple t2();" declares a function named t2 that returns a tuple, not an actual tuple. Leave off the extra parentheses to get a working version.

Why I cannot access the first element (it works if I give an initial value, for instance using  tuple t2(1);  I get a similar error if I use the method get<N>() instead of the function.

Adding an initial value disambiguates the statement so it is no longer a function declaration. The version of get you use does not matter to this problem. -- Jeremiah Willcock