1 #ifndef STAN_MATH_REV_CORE_OPERATOR_UNARY_PLUS_HPP 2 #define STAN_MATH_REV_CORE_OPERATOR_UNARY_PLUS_HPP
const double NOT_A_NUMBER
(Quiet) not-a-number value.
Independent (input) and dependent (output) variables for gradients.
const double val_
The value of this variable.
vari * vi_
Pointer to the implementation of this variable.
fvar< T > operator+(const fvar< T > &x1, const fvar< T > &x2)
int is_nan(const fvar< T > &x)
Returns 1 if the input's value is NaN and 0 otherwise.