c++ - Problems with std::piecewise_constant_distribution and std::vector -

given bunch of strings i'm trying create program can mimic pseudo-random behaviour weighted distribution based on input.

so far came this

#include <iostream> #include <random> #include <type_traits> #include <map> #include <vector> #include <string> #include <initializer_list>  #define n 100  int main() {     std::vector<std::string> interval{"bread", "castle", "sun"};     std::vector<float> weights { 0.40f, 0.50f, 0.10f };     std::piecewise_constant_distribution<> dist(interval.begin(),                                                 interval.end(),                                                 weights.begin());      std::random_device rd;     std::mt19937 gen(rd()) ;      for(int = 0; i<n;i++)     {         std::cout << dist(gen) << "\n";     }      return(0);  } 

but thing doesn't works , have no clue why, usual usage of std::piecewise_constant_distribution , according online examples, it's std::arrays, i'm trying implement using std::vector, main difference found.

with clang++ output of error is

/usr/bin/../lib/gcc/x86_64-linux-gnu/4.7/../../../../include/c++/4.7/bits/random.tcc:2409:10: error: no matching member function       call 'push_back'                 _m_int.push_back(*__bbegin);                 ~~~~~~~^~~~~~~~~ 

but can't understand because there no explicit .push_back in code, don't coming because debugging templated class it's nightmare , i'm starting one.

anyone having idea why code doesn't work ?

the default result type of std::piecewise_constant_distribution realtype (double here). seems you're trying choose 3 string options various weights, isn't std::piecewise_constant_distribution for. it's designed generate uniform random values numeric intervals given weighting. if modify example , change interval to:

std::vector<double> interval {1, 3, 5, 10, 15, 20}; 

everything compile happily. looks of it, want std::discrete_distribution:

...  std::vector<std::string> interval{"bread", "castle", "sun"}; std::vector<float> weights { 0.40f, 0.50f, 0.10f }; std::discrete_distribution<> dist(weights.begin(), weights.end());  std::mt19937 gen(rd());  for(int = 0; i<n;i++) {     std::cout << interval[dist(gen)] << "\n"; }  ...