parameter_type test fails on MinGW (GCC 15.1)

[swordfatih]

Hi Daniel,

The following test in test\pq\parameter_type.cpp fails to compile on my environment (Windows 11, mingw and GCC 15.1.0) :

static_assert( tao::pq::parameter_type< std::list< std::unordered_set< std::tuple< int > > > > );

The compilation error is :

.../bits/hashtable.h:210:51: error: static assertion failed: hash function must be copy constructible
static_assert(is_copy_constructible<_Hash>::value,

---

My understanding

std::unordered_set<std::tuple<int>> doesn’t work because this MinGW's libstdc++ doesn't seem to provide std::hash<std::tuple<...>> (which is not required by the standard ?)

I could make it work with a specialization of std::hash for std::tuple<Ts...> if this helps to know..