Wrapped inside a promise

[Invander29]

Add a possibility to create std::promise/std::future with stx::Result inside.

auto p = std::promise<stx::Result<A, B>>();
p.set_value(stx::Ok(A{}));

Thank you

[lamarrr]

Hello,

Thanks for your issue.

I've tried this snippet and it works.

Can you perhaps be more detailed by providing the compiler error message, your configuration and compiler name?

[Invander29]

I am using your 1.0.1 version and this code works for me:

auto p = std::promise<Option<int>>();
// or
auto p = std::promise<Option<std::unique_ptr<int>>>();

But Result not

auto p = std::promise<Result<int, int>>();
// or
auto p = std::promise<Result<std::shared_ptr<int>, std::shared_ptr<int>>>();

Visual Studio 2019 (16.6.3) shows:

future(212): error C2280: 'stx::v1::Result<int,int>::Result(void)': attempting to reference a deleted function
stx/internal/option_result.h(1701): message : see declaration of 'stx::v1::Result<int,int>::Result'
stx/internal/option_result.h(1701,3): message : 'stx::v1::Result<int,int>::Result(void)': function was explicitly deleted
future(209): message : while compiling class template member function 'std::_Associated_state<_Ty>::_Associated_state(std::_Deleter_base<_Ty> *)'
2>        with
2>        [
2>            _Ty=stx::v1::Result<int,int>
2>        ]
future(1150): message : see reference to function template instantiation 'std::_Associated_state<_Ty>::_Associated_state(std::_Deleter_base<_Ty> *)' being compiled
2>        with
2>        [
2>            _Ty=stx::v1::Result<int,int>
2>        ]
future(1150): message : see reference to class template instantiation 'std::_Associated_state<_Ty>' being compiled
2>        with
2>        [
2>            _Ty=stx::v1::Result<int,int>
2>        ]
future(1150): message : while compiling class template member function 'std::promise<stx::v1::Result<int,int>>::promise(void)'
cpp(83): message : see reference to function template instantiation 'std::promise<stx::v1::Result<int,int>>::promise(void)' being compiled
cpp(83): message : see reference to class template instantiation 'std::promise<stx::v1::Result<int,int>>' being compiled

[lamarrr]

The fault isn't from STX, rather from the MSVC C++ std lib implementation.
Result, unlike Option is not default-constructible and your MSVC C++ std lib implementation for promise performs a default construction step. Unlike GCC and Clang.

The code compiles on GCC and Clang.

See some similar issues:

https://developercommunity.visualstudio.com/content/problem/60897/c-shared-state-futuresstate-default-constructs-the.html

https://developercommunity.visualstudio.com/content/problem/372171/stdpromise-doesnt-support-types-that-are-not-defau.html

[Invander29]

Ok, thank you.

[lamarrr]

Ok, thank you.

You're welcome