If*this contains a value, returns a reference to the contained value.

Otherwise, throws astd::bad_optional_access exception.

[edit]Parameters

(none)

[edit]Return value

A reference to the contained value.

[edit]Exceptions

std::bad_optional_access if*this does not contain a value.

[edit]Notes

The dereference operatoroperator*() does not check if this optional contains a value, which may be more efficient thanvalue().

[edit]Example

#include <iostream>#include <optional> int main(){std::optional<int> opt={}; try{[[maybe_unused]]int n= opt.value();}catch(conststd::bad_optional_access& e){std::cout<< e.what()<<'\n';} try{        opt.value()=42;}catch(conststd::bad_optional_access& e){std::cout<< e.what()<<'\n';}     opt=43;std::cout<<*opt<<'\n';     opt.value()=44;std::cout<< opt.value()<<'\n';}

bad optional accessbad optional access4344

[edit]See also

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