log1m_exp.hpp

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#ifndef STAN_MATH_FWD_FUN_LOG1M_EXP_HPP
#define STAN_MATH_FWD_FUN_LOG1M_EXP_HPP
 
#include <stan/math/fwd/meta.hpp>
#include <stan/math/fwd/core.hpp>
#include <stan/math/fwd/fun/expm1.hpp>
#include <stan/math/prim/fun/constants.hpp>
#include <stan/math/prim/fun/expm1.hpp>
#include <stan/math/prim/fun/log1m_exp.hpp>
 
namespace stan {
namespace math {
 
template <typename T>
inline fvar<T> log1m_exp(const fvar<T>& x) {
  if (x.val_ >= 0) {
    return fvar<T>(NOT_A_NUMBER);
  }
  return fvar<T>(log1m_exp(x.val_), x.d_ / -expm1(-x.val_));
}
 
}  // namespace math
}  // namespace stan
#endif