https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69449
Bug ID: 69449
Summary: Some invalid fold expressions incorrectly accepted
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: rs2740 at gmail dot com
Target Milestone: ---
Repro:
struct A { A(int = 0); A operator+(A) const; };
struct B { B(int = 0); operator int() const; };
template<int... Is>
void f(){
(A() + A() + ... + A(Is)); // compiles!
}
template<int... Is>
void g(){
(B() + B() + ... + B(Is)); // error: binary expression in operand
// of fold-expression
}
Both function templates should be rejected, because neither A() + A() nor B() +
B() is a cast-expression, but only the one calling the built-in operator + is.
