//===----------------------------------------------------------------------===// // // The LLVM Compiler Infrastructure // // This file is dual licensed under the MIT and the University of Illinois Open // Source Licenses. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // <functional> // template <class T> // struct hash // : public unary_function<T, size_t> // { // size_t operator()(T val) const; // }; // Not very portable #include <system_error> #include <cassert> #include <type_traits> void test(int i) { typedef std::error_code T; typedef std::hash<T> H; static_assert((std::is_same<H::argument_type, T>::value), "" ); static_assert((std::is_same<H::result_type, std::size_t>::value), "" ); H h; T ec(i, std::system_category()); assert(h(ec) == i); } int main() { test(0); test(2); test(10); }