When I try to compile this,
#include <iostream>
struct K{
const static int a = 5;
};
int main(){
K k;
std::cout << std::min(k.a, 7);
}
I get following. Both gcc and clang gives similar error:
/tmp/x-54e820.o: In function `main':
x.cc:(.text+0xa): undefined reference to `K::a'
clang-3.7: error: linker command failed with exit code 1 (use -v to see invocation)
if I do following, it compiles without problem. Is this related to the way std::min is written?
#include <iostream>
struct K{
const static int a = 5;
};
int main(){
K k;
std::cout << std::min((int) k.a, 7); // <= here is the change!!!
}
another way to avoid the error is if I do my own min():
template <class T>
T min(T const a, T const b){
return a < b ? a : b;
}
C-like preprocessor MIN also works OK.