https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102804
Bug ID: 102804
Summary: template matching fails w/ false ambiguity on ternary
expressions with enums
Product: gcc
Version: 11.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: rudick at gmail dot com
Target Milestone: ---
E.g. w/ -std=c++11
#include <iostream>
int main() {
enum: unsigned int32_t { FOO, BAR } foobar = FOO;
std::cout << ((time(nullptr) % 2) ? foobar : 13) << std::endl;
}
The initial error is:
error: ambiguous overload for ‘operator<<’ (operand types are ‘std::ostream’
{aka ‘std::basic_ostream<char>’} and ‘unsigned int’)
in gcc9.2 & gcc 11.2.0
gcc7 happily compiles the code.
with -Wextra, all 3 versions warn:
error: enumerated and non-enumerated type in conditional expression
Version: 11.2.0
system: CentOS Linux 7.7.1908 on Intel Xeon
command: g++ -Wall -Wextra -std=c++11 20211017-bug.cpp
