https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67658
Bug ID: 67658
Summary: [concepts] invalid code with constrained concepts
compiles
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: ryan.burn at gmail dot com
Target Milestone: ---
This code compiles with gcc
g++ (GCC) 6.0.0 20150915 (experimental)
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
//////////////////////////////////////////////////////
template<class T> concept bool C1() { return false; }
template<C1 T> concept bool C2() { return true; }
void f(C2 x) {
}
struct A {} a;
int main() {
f(a);
}
//////////////////////////////////////////////////////
>From page 17 example 6.3 of N4377
(http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4377.pdf), it looks
like constrained concepts are not allowed. And even if they were, the
constraints on concept C2 should not be satisfied.
