Hi,
I am currently facing a strange behavior of the compiler when using
static const class members in C++14 mode as described below. I tested
this with gcc versions 4.9.2 (self-build) and 5.1.0 (from Ubuntu
repositories). The reproducer is the following:
### test.cpp ###
#include <utility>
class TestClass {
public:
static const int ID = 0;
};
void doStuff () {
auto t = std::make_pair(TestClass::ID, TestClass::ID);
}
//void doStuff1 () {
// auto t = static_cast<int>(TestClass::ID);
//}
### END test.cpp ###
If I compile this test program into an object file and check the
undefined symbols, I get this:
# g++ test.cpp -c -std=c++14
# nm -C test.o | grep ID
U TestClass::ID
If the very same test program is compiled with -O1 or higher
optimization levels, the symbol TestClass::ID is not undefined anymore.
Basically, it does not even occur in the object file. Likewise, if I
replace doStuff with doStuff1 and run the compilation again with -O0,
the symbol is _NOT_ undefined.
Is this behavior expected? And if so, what is the reason for this
behavior? Since clang behaves the same way: Is the code possibly buggy?
Thank you for your support in advance and best regards,
Andi
I would like to ask if someone could explain if this behavior is as
expected and i
--
Karlsruhe Institute of Technology (KIT)
Department of Measurement and Control (Institut für Mess- und Regelungstechnik)
André-Marcel Hellmund, M.Sc.
Wissenschaftlicher Mitarbeiter
Engler-Bunte-Ring 21
76131 Karlsruhe, Germany
Geb. 40.32, Zi. 033
Phone: +49 721 608-47146
Email: andre-marcel.hellmund@xxxxxxx
Web: www.mrt.uni-karlsruhe.de
_________________________________________________________________________
KIT - Universität des Landes Baden-Württemberg und nationales Großforschungszentrum in der Helmholtz-Gemeinschaft
