Function extern_spec_std_option_T_Option_T_map 

pub fn extern_spec_std_option_T_Option_T_map<T, U, F: FnOnce(T) -> U>(
    self_: Option<T>,
    f: F,
) -> Option<U>

extern spec for ::std::option::Option<T>::map<U, F>

This is not a real function: its only use is for documentation.

requires

match self {
                    None => true,
                    Some(t) => f.precondition((t,)),
                }

ensures

match self {
                    None => result == None,
                    Some(t) => exists<r> result == Some(r) && f.postcondition_once((t,), r),
                }