just fails with a lambda with capture #144
Description
#include <beman/execution/execution.hpp>
#include <stdexec/execution.hpp>
namespace bex = beman::execution;
namespace sex = stdexec;
int main() {
double d = 19.0;
auto j1 = bex::just([](auto l) { return l; },
[d](auto r) { return d; });
auto j2 = sex::just([](auto l) { return l; },
[d](auto r) { return d; });
return 0;
}
https://compiler-explorer.com/z/3bf7M4E5e
<source>:9:15: error: no matching function for call to object of type 'const ::beman::execution::just_t' (aka 'const just_t< ::beman::execution::set_value_t>')
9 | auto j1 = bex::just([](auto l) { return l; },
| ^~~~~~~~~
/opt/compiler-explorer/libs/beman_execution/main/include/beman/execution/detail/just.hpp:31:10: note: candidate template ignored: constraints not satisfied [with T = <(lambda at <source>:9:25), (lambda at <source>:10:25)>]
31 | auto operator()(T&&... arg) const {
| ^
/opt/compiler-explorer/libs/beman_execution/main/include/beman/execution/detail/just.hpp:30:78: note: because '::std::decay_t<(lambda at <source>:10:25)>' (aka '(lambda at <source>:10:25)') does not satisfy 'movable'
30 | requires ::beman::execution::detail::just_size<Completion, T...> && (::std::movable<::std::decay_t<T>> && ...)
| ^
/opt/compiler-explorer/gcc-snapshot/lib/gcc/x86_64-linux-gnu/16.0.0/../../../../include/c++/16.0.0/concepts:274:10: note: because 'assignable_from<(lambda at <source>:10:25) &, (lambda at <source>:10:25)>' evaluated to false
274 | && assignable_from<_Tp&, _Tp> && swappable<_Tp>;
| ^
/opt/compiler-explorer/gcc-snapshot/lib/gcc/x86_64-linux-gnu/16.0.0/../../../../include/c++/16.0.0/concepts:152:10: note: because '__lhs = static_cast<_Rhs &&>(__rhs)' would be invalid: object of type '(lambda at <source>:10:25)' cannot be assigned because its copy assignment operator is implicitly deleted
152 | { __lhs = static_cast<_Rhs&&>(__rhs) } -> same_as<_Lhs>;
| ^
1 error generated.
Compiler returned: 1