https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80251
Bug ID: 80251
Summary: Is the is_aggregate meta function missing?
Product: gcc
Version: 7.0.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: gcc-bugs at marehr dot dialup.fu-berlin.de
Target Milestone: ---
Hi gcc-team,
is is_aggregate [1] really missing or is it within some experimental
namespaces?
If I try to compile the following:
```c++
#include <type_traits>
struct aggregate_t {
int foo;
int bar;
};
int main() {
aggregate_t foo;
static_assert(std::is_aggregate_v<decltype(foo)>>);
return 0;
}
```
It will result in the following error:
```terminal
bug_gcc_is_aggregate.cpp: In function ‘int main()’:
bug_gcc_is_aggregate.cpp:10:22: error: ‘is_aggregate_v’ is not a member of
‘std’
static_assert(std::is_aggregate_v<decltype(foo)>>);
^~~~~~~~~~~~~~
bug_gcc_is_aggregate.cpp:10:22: note: suggested alternative: ‘is_array_v’
static_assert(std::is_aggregate_v<decltype(foo)>>);
^~~~~~~~~~~~~~
is_array_v
bug_gcc_is_aggregate.cpp:10:37: error: expected primary-expression before
‘decltype’
static_assert(std::is_aggregate_v<decltype(foo)>>);
^~~~~~~~
bug_gcc_is_aggregate.cpp:10:37: error: expected ‘,’ before ‘decltype’
bug_gcc_is_aggregate.cpp:10:37: error: expected string-literal before
‘decltype’
bug_gcc_is_aggregate.cpp:10:37: error: expected ‘)’ before ‘decltype’
zsh: exit 1 g++-7 -std=gnu++1z -Wall -Wextra bug_gcc_is_aggregate.cpp
```
[1] http://en.cppreference.com/w/cpp/types/is_aggregate
