> On Dec. 17, 2013, 11:35 p.m., Benjamin Hindman wrote: > > 3rdparty/libprocess/3rdparty/stout/tests/option_tests.cpp, lines 87-89 > > <https://reviews.apache.org/r/16332/diff/1/?file=398977#file398977line87> > > > > Any reason not to do: > > > > Option<Option<int> > someNone1 = Some(None()); > > Option<Option<int> > noneNone1 = None(); > > Jiang Yan Xu wrote: > Ambiguity. We probably would never use it this way but just for > theoretical possibility. > > ../../../../3rdparty/libprocess/3rdparty/stout/tests/option_tests.cpp: In > member function ‘virtual void OptionTest_Comparison_Test::TestBody()’: > ../../../../3rdparty/libprocess/3rdparty/stout/tests/option_tests.cpp:88: > error: conversion from ‘_Some<None>’ to ‘Option<Option<int> >’ is ambiguous > ../../../../3rdparty/libprocess/3rdparty/stout/include/stout/some.hpp:22: > note: candidates are: _Some<T>::operator Option<U>() const [with U = > Option<int>, T = None] > ../../../../3rdparty/libprocess/3rdparty/stout/include/stout/some.hpp:29: > note: _Some<T>::operator S<Option<U> >() const [with S = > Option, U = int, T = None] > ../../../../3rdparty/libprocess/3rdparty/stout/tests/option_tests.cpp:89: > error: conversion from ‘None’ to ‘Option<Option<int> >’ is ambiguous > ../../../../3rdparty/libprocess/3rdparty/stout/include/stout/none.hpp:18: > note: candidates are: None::operator Option<T>() const [with T = Option<int>] > ../../../../3rdparty/libprocess/3rdparty/stout/include/stout/none.hpp:27: > note: None::operator S<Option<T> >() const [with S = Option, > T = int]
I can do this though: Option<Option<int> > someNone1 = Option<Option<int> >::some(None()); - Jiang Yan ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/16332/#review30581 ----------------------------------------------------------- On Dec. 17, 2013, 11:21 p.m., Jiang Yan Xu wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/16332/ > ----------------------------------------------------------- > > (Updated Dec. 17, 2013, 11:21 p.m.) > > > Review request for mesos, Benjamin Hindman, Ben Mahler, Jie Yu, and Vinod > Kone. > > > Repository: mesos-git > > > Description > ------- > > Used in a future patch to compare "UPID from" with "Option<UPID> master". > > > Diffs > ----- > > 3rdparty/libprocess/3rdparty/stout/include/stout/option.hpp > f12c0cafad141fe8857fbc14624ce43e3de77171 > 3rdparty/libprocess/3rdparty/stout/tests/option_tests.cpp > bda06104f30d7358e0f8829e62e5363954355658 > > Diff: https://reviews.apache.org/r/16332/diff/ > > > Testing > ------- > > make check. > > > Thanks, > > Jiang Yan Xu > >
