I have a bimap like this:
using MyBimap = boost::bimaps::bimap<
boost::bimaps::unordered_set_of<A>,
boost::bimaps::unordered_set_of<B>>;
I want to construct it from a static initializer list, as it can be done for std::map
:
MyBimap map{{a1, b1}, {a2, b2}, {a3, b3}};
Unfortunately, it doesn't work because bimap
doesn't support initializer lists, so I tried a workaround. Boost's documentation lists the following constructors:
bimap();
template< class InputIterator >
bimap(InputIterator first,InputIterator last);
bimap(const bimap &);
So I tried the second one, like this:
std::vector<std::pair<A,B>> v{{a1, b1}, {a2, b2}, {a3, b3}};
MyBimap map(v.begin(), v.end());
It also didn't work. The documentation isn't exactly clear what kind of iterators this constructor expects, but apparently it's not simply an iterator of std::pair<A, B>
objects. Then what does this constructor expect for this kind of bimap?
The iterator begin/end should be for a sequence of bimap values.
boost::bimap< A, B>::value_type
A bimap value is a lot like a std::pair and can be initialized with {a1, b1}
syntax. A vector of them seems to work too, which provides usable iterators for the constructor.
Ok, here is an example that compiles and runs for me (gcc 4.8.2 --std=c++11)
#include <vector>
#include <boost/bimap.hpp>
using namespace std;
int main() {
typedef boost::bimap< int, int > MyBimap;
std::vector<MyBimap::value_type > v{{1, 2}, {3, 4}, {5, 6}};
MyBimap M(v.begin(),v.end());
std::cout << "The size is " << M.size()
<< std::endl;
std::cout << "An entry is 1:" << M.left.at(1)
<< std::endl;
}