https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96106
Bug ID: 96106
Summary: A friend abbreviated template function denies access
to private members
Product: gcc
Version: 10.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: kirshamir at gmail dot com
Target Milestone: ---
template<typename T>
class number {
T num;
public:
number(T num = 0): num(num) {}
friend auto add(auto a, auto b);
};
auto add(auto a, auto b) {
// unjustified compilation error on the line below
return number{a}.num + number{b}.num;
}
int main() {
auto result = add(1.0, 2.0);
}
Compilation error provided by gcc (version 10.1 with -std=c++20):
In instantiation of 'auto add(auto:13, auto:14) [with auto:13 = double; auto:14
= double]':
error: 'double number<double>::num' is private within this context
return number{a}.num + number{b}.num;
See also:
https://stackoverflow.com/questions/62779488/a-friend-abbreviated-template-function-clang-and-gcc-differ
