/************************************************************************************* Grid physics library, www.github.com/paboyle/Grid Source file: ./gcc-bug-report/broken.cc Copyright (C) 2015 Author: Peter Boyle <paboyle@ph.ed.ac.uk> This program 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 2 of the License, or (at your option) any later version. This program 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 program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. See the full license in the file "LICENSE" in the top level distribution directory *************************************************************************************/ /* END LEGAL */ #include <vector> #include <complex> #include <type_traits> #include <iostream> typedef std::complex<double> ComplexD; template <class T> class TypeMapper { public: enum { NestLevel = T::NestLevel }; }; template<> class TypeMapper<ComplexD> { public: enum { NestLevel = 0 }; }; template<class obj> class Container { public: std::vector<obj> data; Container(int size) : data (size){}; }; template<class obj> class Recursive { public: enum { NestLevel = TypeMapper<obj>::NestLevel + 1}; obj internal; }; template<int N,class obj,typename std::enable_if<N==obj::NestLevel >::type * = nullptr > auto function(const obj &arg)-> obj { std::cout<<GridLogMessage<<"Leaf "<<obj::NestLevel<<std::endl; return arg; } template<int N,class obj,typename std::enable_if<N!=obj::NestLevel >::type * = nullptr > auto function(const obj &arg)-> obj { std::cout<<GridLogMessage<<"Node "<<obj::NestLevel<<std::endl; obj ret; ret.internal=function<N>(arg.internal); return ret; } template<int N,class obj> auto function(const Container<obj> & arg)-> Container<decltype(function<N>(arg.data[0]))> { Container<decltype(function<N>(arg.data[0]))> ret(arg.data.size()); for(int ss=0;ss<arg.data.size();ss++){ ret.data[ss] = function<N>(arg.data[ss]); } return ret; } int main(int argc,char **argv) { Container<Recursive<Recursive<ComplexD> > > array(10); Container<Recursive<Recursive<ComplexD> > > ret(10); ret = function<1>(array); ret = function<2>(array); }