In Class.h
:
class Class {
public:
template <typename T> void function(T value);
};
In Class.cpp
:
template<typename T> void Class::function(T value) {
// do sth
}
In main.cpp
:
#include "Class.h"
int main(int argc, char ** argv) {
Class a;
a.function(1);
return 0;
}
I get a linker error because Class.cpp
never instantiates void Class::function<int>(T)
.
You can explicitly instantiate a class template with :
template class std::vector<int>;
How do you explicitly instantiate a member template of a non-template class ?
You can use the following syntax in Class.cpp
:
template void Class::function(int);
The template argument can be omitted because of type deduction, which works for function templates. Thus, the above is equivalent to the following, just more concise:
template void Class::function<int>(int);
Notice, that it is not necessary to specify the names of the function parameters - they are not part of a function's (or function template's) signature.