On Thu, Apr 12, 2012 at 6:13 AM, Mathias Gaunard < mathias.gaunard@ens-lyon.org> wrote:
On 12/04/12 10:36, Robert Jones wrote:
On Wed, Apr 11, 2012 at 11:33 PM, Robert Dailey<rcdailey.lists@gmail.** com <rcdailey.lists@gmail.com>>wrote:
Is there a method in the boost library to iterate a vector of
boost::tuple objects, comparing the 1st element in the tuple of each tuple to a value that I specify? My tuple is setup like so:
typedef boost::tuple<int, int, char const*> Tuple; typedef std::vector<Tuple> ErrorStringMap;
ErrorStringMap mystrings = tuple_list_of (10, "10", "ten") (20, "20", "twenty") (30, "30", "thirty") (10, "10", "ten");
I want to search the vector of tuples and do something with every tuple that has the number 10 as the first element in the tuple.
*** Not Tested or Compiled ***
#include<boost/range.hpp> #include<boost/range/adaptors/**filtered.hpp> // ... and maybe some other range headers #include<boost/bind.hpp>
for_each( mystrings | boost::adaptors::filtered( boost::bind( get<0>, _1 ) == 10 ), yourAction );
You probably can't take the address of get<0>.
Also, you could remove the dependence on filtered by using find_if instead of for_each.
I can't use phoenix, I'm still on boost 1.46.1. I try the following with boost::lambda: using namespace boost::lambda; using boost::lambda::_1; using boost::lambda::bind; ErrorStringMap::const_iterator it = std::find_if( mystrings.begin(), mystrings.end(), bind(&Tuple::get<0>, _1) == error_code ); if( it != mystrings.end() ) { return *it; } However I keep getting compiler error C2780, saying it's expecting N number of arguments. I'm on MSVC9. Why can't I get lambda to work??