// Copyright (C) 2018-2019 Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the // terms of the GNU General Public License as published by the // Free Software Foundation; either version 3, or (at your option) // any later version. // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // You should have received a copy of the GNU General Public License along // with this library; see the file COPYING3. If not see // . // { dg-options "-std=gnu++2a" } // { dg-do compile { target c++2a } } #include template constexpr auto test(UInt x) -> decltype(std::popcount(x)) { static_assert( noexcept(std::popcount(x)) ); constexpr unsigned digits = std::numeric_limits::digits; static_assert( std::popcount((UInt)0) == 0 ); static_assert( std::popcount((UInt)-1) == digits ); static_assert( std::popcount((UInt)-2) == digits - 1 ); static_assert( std::popcount((UInt)127) == 7 ); static_assert( std::popcount((UInt)1) == 1 ); static_assert( std::popcount((UInt)2) == 1 ); static_assert( std::popcount((UInt)0x70) == 3 ); if constexpr (std::numeric_limits::digits > 8) { static_assert( std::popcount((UInt)(0x101)) == 2 ); static_assert( std::popcount((UInt)(0xfff)) == 12 ); } if constexpr (std::numeric_limits::digits > 64) { static_assert( std::popcount((UInt)0xffffffffffffffff) == 64 ); static_assert( std::popcount(0x5555555555555555 | ((UInt)1 << 64)) == 33 ); static_assert( std::popcount(0x5555555555555555 | ((UInt)3 << 64)) == 34 ); } return true; } static_assert( test( (unsigned char)0 ) ); static_assert( test( (unsigned short)0 ) ); static_assert( test( (unsigned int)0 ) ); static_assert( test( (unsigned long)0 ) ); static_assert( test( (unsigned long long)0 ) ); // std::popcount(T) shall not participate in overload resolution // unless T is an unsigned integer type. struct X { constexpr bool did_not_match() { return true; } }; constexpr X test(...) { return X{}; } static_assert( test( (bool)0 ).did_not_match() ); static_assert( test( (char)0 ).did_not_match() ); static_assert( test( (int)0 ).did_not_match() ); static_assert( test( (char16_t)0 ).did_not_match() ); static_assert( test( (float)0 ).did_not_match() ); static_assert( test( (void*)0 ).did_not_match() ); static_assert( test( X{} ).did_not_match() ); enum E : unsigned { e }; static_assert( test( e ).did_not_match() ); #if !defined(__STRICT_ANSI__) && defined _GLIBCXX_USE_INT128 static_assert( test( (unsigned __int128)0 ) ); static_assert( test( (__int128)0 ).did_not_match() ); #endif #if defined(__GLIBCXX_TYPE_INT_N_0) static_assert( test( (unsigned __GLIBCXX_TYPE_INT_N_0)0 ) ); static_assert( test( (__GLIBCXX_TYPE_INT_N_0)0 ).did_not_match() ); #endif #if defined(__GLIBCXX_TYPE_INT_N_1) static_assert( test( (unsigned __GLIBCXX_TYPE_INT_N_1)0 ) ); static_assert( test( (__GLIBCXX_TYPE_INT_N_1)0 ).did_not_match() ); #endif #if defined(__GLIBCXX_TYPE_INT_N_2) static_assert( test( (unsigned __GLIBCXX_TYPE_INT_N_2)0 ) ); static_assert( test( (__GLIBCXX_TYPE_INT_N_2)0 ).did_not_match() ); #endif #include static_assert( test( (std::byte)0 ).did_not_match() );