https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63628
Bug ID: 63628
Summary: [c++1y] cannot use decltype on captured variable in
generic lambda
Product: gcc
Version: 5.0
Status: UNCONFIRMED
Keywords: rejects-valid
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: redi at gcc dot gnu.org
CC: daniel.kruegler at googlemail dot com, jason at gcc dot
gnu.org,
oakad at yahoo dot com, tongari95 at gmail dot com
Blocks: 54367
+++ This bug was initially created as a clone of Bug #61814 +++
The code below has a lambda that captures the outer params t, for forwarding
matter, decltype on t has to be used.
```
auto const pack = [](auto&&... t)
{
return [&](auto&& f)->decltype(auto)
{
return f(static_cast<decltype(t)>(t)...);
};
};
int main(int argc, char** argv) {
pack(1)([](int){});
return 0;
}
```
It works with clang 3.5, but g++ 4.9.0 complains:
error: 't' was not declared in this scope
The same also applies to `sizeof` or that kind of compile-time thing.
