How to solve ambiguous function overload due to default constructor in parameter

Question

Let's say I have this class:

class Foo {
public:
   void member(std::string s);
   void member(int64_t &n);
};

Now I want to do some thing like

int64_t value = 5;
Foo f;
f.member(value);

The problem is that the compiler (at least GCC) gets confused & believes I'm trying to call member with a string using the char* constructor:

invalid conversion from 'int64_t' to 'const char*

How could I go about calling the actual member function I want without changing the method signature? Are templates the only solution? I have tried casting without any help (which shouldn't matter since the type is already unambiguous).

---

Sorry - found the mistake.

The declaration was:

class Foo {
public:
    void member(std::string s);
    void member(int64_t &n);
};

Removing the by-ref solved it.

Answer 1

Cast the argument to exactly match the argument type of the overload you want:

f.member((int64_t) value);

Answer 2

There may be easier ways to solve this (like with a parameter cast) but I have seen solutions that look like the following:

void (Foo::*memberProc)(int64_t) = &Foo::member;

Foo f;
((f).*(memberProc))(5);

Convoluted, yes, but it's explicit.

Answer 3

Sorry - found the mistake.

The declaration was:

class Foo {
public:
   void member(std::string s);
   void member(int64_t &n);
};

Removing the by-ref solved it.