Help with a boost::lambda problem and boost::array?
Is there a solution?
It appeared to me that the likely winner was:
http://www.boost.org/doc/libs/1_37_0/doc/html/lambda/extending.html
Then it seems we would use the boost array's typedef value_type to get the
return type. However, I do not see operator[] overloading in the list of
supporting operators here.
But the following code compiles:
//Testing lambda and vectors/arrays.
using lambda::_1;
std::vector<Real> vec(1);
vec[1] = 0;
boost::function
Hello
I don't know why this version works
std::vector<Real> vec(2);
vec[0] = 1; vec[1] = 2;
boost::function
Is there a solution?
It appeared to me that the likely winner was:
http://www.boost.org/doc/libs/1_37_0/doc/html/lambda/extending.html
Then it seems we would use the boost array's typedef value_type to get the
return type. However, I do not see operator[] overloading in the list of
supporting operators here.
But the following code compiles:
//Testing lambda and vectors/arrays.
using lambda::_1;
std::vector<Real> vec(1);
vec[1] = 0;
boost::function
AMDG Max wrote:
I don't know why this version works
std::vector<Real> vec(2); vec[0] = 1; vec[1] = 2; boost::function
vec_f = _1[0]; //Returns the 0'th element. boost::function vec_f1 = _1[0] * _1[1]; but this one doesn't.
std::vector<Real> vec(2); vec[0] = 1; vec[1] = 2; boost::function
vec_f = _1[0]; //Returns the 0'th element. boost::function vec_f1 = _1[0] * _1[1];
The handling of const is wrong in boost/lambda/detail/operator_return_type_traits.hpp The containers start on line 894. In Christ, Steven Watanabe
Considering also that neither
typedef boost::array
I don't know why this version works
std::vector<Real> vec(2); vec[0] = 1; vec[1] = 2; boost::function
vec_f = _1[0]; //Returns
the
0'th element. boost::function
vec_f1 = _1[0] * _1[1]; but this one doesn't.
std::vector<Real> vec(2); vec[0] = 1; vec[1] = 2; boost::function
vec_f = _1[0]; //Returns the 0'th element. boost::function vec_f1 = _1[0] * _1[1]; B/Rgds Max
AMDG jesseperla@gmail.com wrote:
Is there a solution?
It appeared to me that the likely winner was: http://www.boost.org/doc/libs/1_37_0/doc/html/lambda/extending.html
Then it seems we would use the boost array's typedef value_type to get the return type. However, I do not see operator[] overloading in the list of supporting operators here.
That's a documentation problem. It's other_action
But the following code compiles: //Testing lambda and vectors/arrays. using lambda::_1; std::vector<Real> vec(1); vec[1] = 0; boost::function
vec_f = _1[0]; //Returns the 0'th element. Hence, it seems that this type of action is supported. Any idea where the sourcecode for the std::vector lambda operators are? might be useful to just copy/paste.
It's all in boost/lambda/detail/operator_return_type_traits.hpp
Also, I wonder if there is any way to do this generically for all vector/array types supporting the Container concept? (I use a lot of ublas::vectors). And if operator() is also supported, I use a lot of ublas::matrix as well, so this would be nice to have in lambda.
In Christ, Steven Watanabe
participants (3)
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jesseperla＠gmail.com -
Max -
Steven Watanabe