https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67934
Bug ID: 67934
Summary: [concepts] ICE when providing default function
implementations using concepts
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: michel.steuwer at gmail dot com
Target Milestone: ---
Created attachment 36483
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36483&action=edit
Contains test case with preprocessed file.
The following code fails with an ICE:
===
#include <iostream>
template <typename T>
concept bool
JustEqualityComparable() {
return requires(T a, T b) {
{ a == b } -> bool;
};
}
template <typename T>
concept bool
JustInequalityComparable() {
return requires(T a, T b) {
{ a != b } -> bool;
};
}
bool operator==(const JustInequalityComparable& a1,
const JustInequalityComparable& a2) {
return !(a1 != a2);
}
bool operator!=(const JustEqualityComparable& a1,
const JustEqualityComparable& a2) {
return !(a1 == a2);
}
template <typename T>
requires JustEqualityComparable<T>()
bool useEq(T t1, T t2) {
return t1 == t2;
}
struct A {
int a;
};
bool operator==(const A& a1, const A& a2) {
return a1.a == a2.a;
}
int main() {
using namespace std;
cout << boolalpha << useEq(A{4}, A{6}) << "\n";
return 0;
}
===
~/bin/gcc/bin/g++ -std=c++1z -save-temps foo.cpp
g++: internal compiler error: Segmentation fault (program cc1plus)
Removing either the operator in line 19 or 24 makes the program compile.
Replacing the operator implemented with concepts in line 19 by a plain template
version makes the program compile as well.
