How can I prevent implicit conversions in a function template?

Question

How can I define a function template to prevent implicit conversions?

It seems I can prevent implicit conversions using non-template functions but not using function

Answer 1

The following overload will prevent implicit conversions:

template <class T>
void no_conversions(T) = delete; // 7

void no_conversions(const B&) {} // 8

and leads to:

// Requested behaviour.
no_conversions(a); // resolves to 7
no_conversions(b); // resolves to 8

A value-overload poisons the overload set for implicit conversions as it will be an exact match.

Edit:

template <class T>
void no_conversions(const T&) = delete; // 9

void no_conversions(const B&) {}        // 10

works just as well.