Function lyd_eval_xpath 

pub unsafe extern "C" fn lyd_eval_xpath(
    ctx_node: *const lyd_node,
    xpath: *const c_char,
    result: *mut ly_bool,
) -> Type

@brief Evaluate an XPath on data and return the result converted to boolean.

Optimizations similar as in ::lyd_find_xpath().

@param[in] ctx_node XPath context node. @param[in] xpath [XPath](@ref howtoXPath) to select in JSON format. @param[out] result Expression result converted to boolean. @return LY_SUCCESS on success, @p result is returned. @return LY_ERR value if an error occurred.