operator_unary_negative.hpp

Go to the documentation of this file.

#ifndef __STAN__AGRAD__REV__OPERATOR_UNARY_NEGATIVE_HPP__
#define __STAN__AGRAD__REV__OPERATOR_UNARY_NEGATIVE_HPP__

#include <stan/agrad/rev/var.hpp>
#include <stan/agrad/rev/op/v_vari.hpp>

namespace stan {
  namespace agrad {
    
    namespace {
      class neg_vari : public op_v_vari {
      public: 
        neg_vari(vari* avi) :
        op_v_vari(-(avi->val_), avi) {
        }
        void chain() {
          avi_->adj_ -= adj_;
        }
      };
    }

    inline var operator-(const var& a) {
      return var(new neg_vari(a.vi_));
    }

  }
}
#endif