Author
anonymous
over 6 years ago
Language
C++
Compiler
gcc 9.1.0
Options
Warnings
Boost 1.70.0
C++2a(GNU)
no pedantic
Author
anonymous
over 6 years ago
$ g++ prog.cc -Wall -Wextra -I/opt/wandbox/boost-1.70.0/gcc-9.1.0/include -std=gnu++2a prog.cc: In instantiation of 'struct conjunction<valid_except_void<void> >':
prog.cc:5:39: required from 'struct conjunction<valid_except_void<int>, valid_except_void<void> >'
prog.cc:10:42: required from 'constexpr const auto test<int, void>'
prog.cc:12:23: required from here
prog.cc:5:39: error: no match for 'operator&&' (operand types are 'valid_except_void<void>' and 'conjunction<>')
5 | std::integral_constant<bool, B1{} && conjunction<Bn...>{}> { };
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~
prog.cc:5:39: note: candidate: 'operator&&(bool, std::integral_constant<bool, true>::value_type {aka bool})' <built-in>
prog.cc:5:39: note: no known conversion for argument 1 from 'valid_except_void<void>' to 'bool'
prog.cc: In instantiation of 'struct conjunction<valid_except_void<int>, valid_except_void<void> >':
prog.cc:10:42: required from 'constexpr const auto test<int, void>'
prog.cc:12:23: required from here
prog.cc:5:39: error: no match for 'operator&&' (operand types are 'valid_except_void<int>' and 'conjunction<valid_except_void<void> >')
prog.cc:5:39: note: candidate: 'operator&&(std::integral_constant<bool, false>::value_type {aka bool}, bool)' <built-in>
prog.cc:5:39: note: no known conversion for argument 2 from 'conjunction<valid_except_void<void> >' to 'bool'
prog.cc: In instantiation of 'constexpr const auto test<int, void>':
prog.cc:12:23: required from here
prog.cc:10:42: error: 'value' is not a member of 'conjunction<valid_except_void<int>, valid_except_void<void> >'
10 | template <typename... Ts> constexpr auto test = /*std::*/conjunction<valid_except_void<Ts>...>::value;
| ^~~~
prog.cc:12:23: error: unable to deduce 'const auto' from 'test<int, void>'
12 | constexpr auto inst = test<int, void>;
| ^~~~~~~~~~~~~~~
prog.cc:12:16: warning: 'inst' defined but not used [-Wunused-variable]
12 | constexpr auto inst = test<int, void>;
| ^~~~
Exit Code:
1