c++ explicit multi-arg constructor ambiguity

I'm encountering an unexpected issue in some code I'm writing now and I'm not sure which compiler is correct.

We have a multi-argument constructor which takes const char*, const char*, but it is declared explicit:

constexpr explicit Wrapper(const char* a, const char* b) : pair(a,b){}

And then we have a function which takes Wrapper and an overload which takes a std::pair<const char*, const char*>

void q(Wrapper w); void q(std::pair<const char *, const char *> w);

And then we have code like this, which I would expect to call the second overload:

q({"a", "b"});

This compiles fine on clang, but fails to compile on both GCC and MSVC. I've been trying to look for any mention of explicit multi-arg constructor in the standard and if there's anything mentioning this ambiguity but I haven't found the relevant text. I'm just wondering which behavior is correct and which is wrong?

godbolt link: http://ift.tt/2eJMRMH