Function extern_spec_std_option_T_Option_T_replace 

pub fn extern_spec_std_option_T_Option_T_replace<T>(
    self_: &mut Option<T>,
    value: T,
) -> Option<T>

extern spec for ::std::option::Option<T>::replace

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

terminates

ghost

ensures

result == *self && ^self == Some(value)