extern_spec_std_time_Instant_checked_sub

creusot_contracts::std::time

Function extern_spec_std_time_Instant_checked_sub 

Source 
pub fn extern_spec_std_time_Instant_checked_sub(
    self_: &Instant,
    duration: Duration,
) -> Option<Instant>
Expand description

extern spec for ::std::time::Instant::checked_sub

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

terminates

ghost

ensures 

duration@ == 0 ==> result.deep_model() == Some(self@)

ensures 

duration@ > 0 && result != None ==> Some(self@) > result.deep_model()