utx::kspt::wprintable is a concept to constrain a wchar_t based printable types of std::wostream. The type must satisfy printable by std::wostream. Many basic types satisfy utx::wprintable, such as int, float, bool. Specially, std::wstring satisfies utx::kspt::wprintable, but std::string does not satisfy utx::kspt::wprintable, it satisfies utx::kspt::printable.
utx::kspt::wprintable
template <typename type1> concept wprintable = ???;
#include <utxcpp/core.hpp> template <utx::kspt::wprintable type1> class fizz_buzz { public: fizz_buzz(const type1 & value1) { std::wcout << value1 << std::endl; utx::wprint(value1); } }; int main() { fizz_buzz f1{123}; fizz_buzz f2{L"Hello c++!"}; }