Conversion operator template specialization

Question

Here\'s a largely academic exercise in understanding conversion operators, templates and template specializations. The conversion operator template in the following code wo

Answer 1

static_cast here is equivalent of doing std::string(a).

Note that std::string s = std::string(a); doesn't compile either. My guess is, there are plenty of overloads for the constructor, and the template version can convert a to many suitable types.

On the other hand, with a fixed list of conversions, only one of those matches exactly a type that the string's constructor accepts.

To test this, add a conversion to const char* - the non-templated version should start failing at the same place.

(Now the question is why std::string s = a; works. Subtle differences between that and std::string s = std::string(a); are only known to gods.)