https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89062
Bug ID: 89062
Summary: class template argument deduction failure with
parentheses
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: barry.revzin at gmail dot com
Target Milestone: ---
Reduced from StackOverflow https://stackoverflow.com/q/54369677/2069064:
template<class T>
struct Foo {
Foo(T) {}
};
template<class T>
struct Bar {
Bar(T) {};
};
Foo foo(Bar{1});
This fails with:
<source>:11:9: error: 'auto' parameter not permitted in this context
Foo foo(Bar{1});
^~~
Compiler returned: 1
Every other alternative is fine:
Foo foo(Bar(1)); // ok
Foo foo{Bar{1}}; // ok
Foo foo{Bar(1)}; // ok
Foo foo(Bar<int>(1)); // ok
Foo foo(Bar<int>{1}); // ok
Foo<Bar<int>> foo(Bar{1}); // ok
