https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107813
Bug ID: 107813
Summary: Enum with underlying type uint8_t bad promotion for
unsigned char
Product: gcc
Version: og10 (devel/omp/gcc-10)
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: gdrzewo at gmail dot com
Target Milestone: ---
After migration from GCC9 to GCC10+ encountered the problem with printing
underlying types for enum with uint8_t. Below is minimal reproduction. Flooder
is a kind of wrapper for ostream used for logger.
#include <iostream>
enum TEnum: uint8_t {
Kot = 67
};
struct Flooder
{
Flooder(std::ostream& oo): o(oo) {};
std::ostream& o;
template <typename T>
Flooder& operator<<(const T& t)
{
this->o << t;
return *this;
}
};
template<>
Flooder& Flooder::operator<<(const unsigned char& c) {
o << static_cast<unsigned int>(c);
return *this;
}
int main() {
Flooder f(std::cout);
auto cat = TEnum::Kot;
unsigned char dog = 'D';
std::cout << "first is enum uint8_t, second is unsigned char type, both
should be numbers" << std::endl;
f << cat << " vs " << dog << "\n\r";
return 0;
}
Std out
(gcc9)
first is enum uint8_t, second is unsigned char type, both should be numbers
67 vs 68
(gcc10)
first is enum uint8_t, second is unsigned char type, both should be numbers
C vs 68
