operator_unary_decrement.hpp
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#ifndef STAN_MATH_REV_CORE_OPERATOR_UNARY_DECREMENT_HPP
#define STAN_MATH_REV_CORE_OPERATOR_UNARY_DECREMENT_HPP
#include <stan/math/rev/core/var.hpp>
#include <stan/math/rev/core/v_vari.hpp>
#include <stan/math/prim/scal/fun/is_nan.hpp>
#include <limits>
namespace stan {
namespace math {
namespace {
class decrement_vari : public op_v_vari {
public:
explicit decrement_vari(vari* avi) :
op_v_vari(avi->val_ - 1.0, avi) {
}
void chain() {
if (unlikely(is_nan(avi_->val_)))
avi_->adj_ = std::numeric_limits<double>::quiet_NaN();
else
avi_->adj_ += adj_;
}
};
}
inline var& operator--(var& a) {
a.vi_ = new decrement_vari(a.vi_);
return a;
}
inline var operator--(var& a, int /*dummy*/) {
var temp(a);
a.vi_ = new decrement_vari(a.vi_);
return temp;
}
}
}
#endif
is_nan.hpp
stan
Definition: log_sum_exp.hpp:8
stan::math::var
Independent (input) and dependent (output) variables for gradients.
Definition: var.hpp:30
stan::math::operator--
var & operator--(var &a)
Prefix decrement operator for variables (C++).
Definition: operator_unary_decrement.hpp:40
unlikely
#define unlikely(x)
Definition: likely.hpp:9
v_vari.hpp
stan::math::var::vi_
vari * vi_
Pointer to the implementation of this variable.
Definition: var.hpp:42
var.hpp
stan::math::is_nan
int is_nan(const fvar< T > &x)
Returns 1 if the input&#39;s value is NaN and 0 otherwise.
Definition: is_nan.hpp:21

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