https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108683
Bug ID: 108683
Summary: Move Occurs when initializing an aggregate base
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: davidledger at live dot com.au
Target Milestone: ---
```CPP
struct Bar
{
Bar() = delete;
Bar(Bar const &) = delete;
Bar& operator=(Bar const&) = delete;
Bar(Bar&&) = delete;
Bar& operator=(Bar&&) = delete;
explicit Bar(int value) : m_value(value) {}
int m_value;
};
namespace A
{
struct Foo : Bar{}; // this is the only difference.
Bar MakeBar()
{
return Bar(10);
}
}
namespace B
{
struct Foo
{
Bar bar; // this is the only difference.
};
Bar MakeBar()
{
return Bar(10);
}
}
int main()
{
A::Foo foo{ A::MakeBar() };
B::Foo bar{ B::MakeBar() };
}
```
The above example, while failing similarly in clang and GCC. Compiles without
issue on MSVC.
As of C++17:
> An aggregate class or array may include non-aggregate public bases (since
> C++17), members, or elements, which are initialized as described above (e.g.
> copy-initialization from the corresponding initializer clause).
cppreference.
So we have an aggregate here. When using GCC, the following error is presented:
```
<source>: In function 'int main()':
<source>:38:30: error: use of deleted function 'Bar::Bar(Bar&&)'
38 | A::Foo foo{ A::MakeBar() };
| ^
<source>:6:5: note: declared here
6 | Bar(Bar&&) = delete;
| ^~~
Compiler returned: 1
```
I believe this should compile without requiring a move constructor of the base
type.
