I have two classes: ClassA and ClassB. ClassB inherits the ClassA. There is a utility.h-header file included to both classa.cpp and classb.cpp so that I can use the method
round(double number, int precision)
from the utilities.h in both .cpp-files.
When using it in ClassA like this:
double roundANumber(double number, int precision)
{
return Utilities::round(number, precision);
}
it works fine. But when I try to use it in the ClassB like this:
double roundAnotherNumber(double number, int precision)
{
return Utilities::round(number, precision);
}
linker gives me error:
error LNK2005: "double __cdecl Utilities::round(double,int)" (?
round@hUtilities@@YANNH@Z) already defined in classa.obj
and I can't seem to find a reason why this is.
Thank you in advance.
Edit: Added that the Utilities.h only contains this
#include <cmath>
namespace MathUtilities {
double round(double number, int precision) {
int precisionFactor = std::pow(10, precision);
return std::round(number * precisionFactor) / precisionFactor;
}
}
Headers are just parsed as if they were included directly. Thus, you end up duplicating the function definition.
To fix this, use inline:
inline double round(double number, int precision) {...}