Fix Issue #93: Don't return a reference to a local variable in extract_list_front
Fix Issue #93: Don't return a reference to a local variable in extract_list_front

alexeymarkov/RxCpp,alexeymarkov/RxCpp,ReactiveX/RxCpp,ReactiveX/RxCpp,Reactive-Extensions/RxCpp,ReactiveX/RxCpp,Reactive-Extensions/RxCpp,Reactive-Extensions/RxCpp,alexeymarkov/RxCpp