[lambda] Exploring bind syntax.
Using the code snippet below as an example,... #include <vector> #include <algorithm> #include <functional> #include "boost/lambda/lambda.hpp" #include "boost/lambda/bind.hpp" #include <boost/function.hpp> struct S { int methodOfS( ); }; int main( ) { typedef std :: vector<S *> Vec; using namespace boost :: lambda; boost :: function<int( S * )> fn = bind( & S :: methodOfS, _1 ); Vec v; Vec :: iterator match; match = find_if( v.begin( ), v.end( ), bind( fn, _1 ) != fn( * v.begin( ) ) ); // OK match = find_if( v.begin( ), v.end( ), fn( _1 ) != fn( * v.begin( ) ) ); // Fail } I find the line marked 'OK' compiles, but not the line marked 'Fail'. Isn't the very point of Boost.Bind to enable this kind of syntax? Is there a better way to write it than my 'Fail' line, but which will still compile? Thanks, Rob. -- ACCU - Professionalism in programming - http://www.accu.org
AMDG Robert Jones wrote:
int main( ) { typedef std :: vector<S *> Vec; using namespace boost :: lambda;
boost :: function<int( S * )> fn = bind( & S :: methodOfS, _1 ); Vec v; Vec :: iterator match;
match = find_if( v.begin( ), v.end( ), bind( fn, _1 ) != fn( * v.begin( ) ) ); // OK
match = find_if( v.begin( ), v.end( ), fn( _1 ) != fn( * v.begin( ) ) ); // Fail }
I find the line marked 'OK' compiles, but not the line marked 'Fail'. Isn't the very point of Boost.Bind to enable this kind of syntax?
You're talking about boost::lambda::bind, not boost::bind. They are not the same thing.
Is there a better way to write it than my 'Fail' line, but which will still compile?
You need to use the 'OK' line. boost::function doesn't know about boost::lambda::bind. In Christ, Steven Watanabe
participants (2)
-
Robert Jones -
Steven Watanabe